This most stark in Celsius, where the useful range of temperatures where humans can live is compressed into roughly -20 C to 40 C, versus 0 to 100 in Fahrenheit.
Its funny how it is so important to have a wider range of temperatures whereas I most often hear Americans use ranges. And instead of saying "today temps will go up into the 70s" you just give the actual number, "it will go up to 23C", what is the problem with that? You could also say because a celsius degree is greater, the number matters much more and it is often not necessary to give a range like that. Ranges or not, it does not matter. A celsius is certainly small enough that decimals are not necessary for humans day-to-day.
What I also often hear from Americans is that the inch is such a perfect unit and "2.5cm" is so awkward but then I hear "6/8 of an inch" and similar units or the mixing of feet and inch and I just don't get it.
This isn't a feature of either system, it's straight-forward familiarity. I'm sure if the weather man used Kelvin, it wouldn't take me long to figure out how to dress for it.
It's like saying Cyrillic is better than Latin script. Or driving on the left is better than on the right. In reality, it just doesn't matter. Whichever you grow up with will seem like the easier one.
When I think -5C, I know how the temperature will actually feel. Someone who thinks "25F" will feel the same in their head. Same for 25cm, 5 inches, 10kg, 40lbs, 9 stones, 7 shaku, etc. Whatever you grew up with will feel better.
Metric just seems to have won in most of the world, including in countries like the US and Japan which use it in science/industry. It just makes sense to have one standard for communicating with as many other people as possible.
Out of all the examples that you gave, this is the one that doesn't fit your argument. Cyrillic has a wider range of letters which makes it a better fit for certain languages with a specific phonology. I don't remember which language it was, but I remember reading about one of the countries between Russia, Turkey, Iran, etc. switched from their indigenous writing system to Latin script in the 1930s/1940s to enable usage of standard typewriters etc. And just a few years later, they switched again, to Cyrillic script, after finding that Latin script does not fit their language all that well.
You use a subjective opinion on one unit's range as a proxy for all other units. How is the meter (cm, mm, km, etc) trash compared to the foot (inch, yard, mile, etc)? They're objectively better in every regard, not just for scientific purposes but in everyday life.
Come to think of it, it's the first time I'm seeing someone making that sort of statement rather than the usual "it's too difficult to change now" excuse.
1/110 mile = 16 yards = 48 feet. Now you do this for an one-hundred-and-tenth of a kilometer.
Or...
1/3 pound = 1/2 mark = 6 shillings & eightpence = 80 pence. Now you do this for a euro. 1/3 of a euro = , ummm?
The point is, the traditional measures are built out of very highly divisible numbers, which is very useful in certain applications, for example surveying, bartering, baking, etc. Just like the metric measures are built out of powers of ten, which is very useful in certain other applications, like seamlessly moving between scales of magnitude in scientific work.
So freaking what. Use decimals and you can easily convert anything into everything. And you don’t have to rely on those few cases where you can exactly divide.
6.8m = 680cm = 0.0068km, etc.
Who writes out prices in fractions?
Its even worse with baking. Scaling up units from recipes is really hard if you have fractions of different units like tee spoon, table spoon and cup and when ounces can both mean a volume and a weight. (“fl. is not always specified”) No thank you.
Also your examples are really poor, when the base systems keep changing in the same dimensions (e.g. length) there is not benefit at all, just confusion or reluctance to convert to other units because it would be too awkward.
Being able to divide by 2, 3, 4, 5, 6, 8, 9, 10, 11, and 12 is not a "few cases", it's the chief part of the small integers into which stuff often needs to be divided evenly.
If you ever went to the market before decimalisation, you would meet many who write prices in fractions. Something would be priced at X pounds/crowns/marks per Y items/weights. Then, the cost of Z units/weights is XZ/Y. When the coins are highly divisible multiples of each other, you have a lot of choices to be able to pay the exact amount and don't have to bother with getting change back. Even better if we price by the dozens (Y = 12) instead of 10s: 12 has twice as many factors than 10.
I understand that this all requires a certain numeracy however. Thankfully nowadays we can just buy things using their credit cards on Amazon: makes mindless consumption much easier.
Anyway, metric just makes sense for most things. The attachment is cultural. My parents talked about my height and weight in the old units. I still use them and so do government forms.
But there's nothing "good" about the old stuff. It's just what you are used to.
On the other hand, freezing and boiling water makes sense, because you know that you have to drive carefully when the temperature is below 0 C.
The absolute scale of Celsius (as opposed to the size of the degree) isn't the most useful anyway because you tend to use Kelvin for a lot of purposes.
The history of the Fahrenheit scale is actually quite fascinating. It's one of the less famous things to come out of the Dutch eighteenth century scientific community. Daniel Fahrenheit picked a few reference points to calibrate thermometers. None of these have anything to do with your level of comfort. That was never a thing or an intention.
Zero was the temperature of a particular mixture of ammonium chloride and water and ice (a brine basically) reaching an equilibrium. The second point (30) was picked as the temperature of water with ice floating in it. The main point was to make this somewhat of a repeatable process. Basically water with ice in it has a very stable temperature because the transition from ice to water takes a lot of energy. Tossing in some ammonium chloride in a known quantity gives you a second point of reference that is different enough that it is meaningful.
Daniel Fahrenheit was using those two points to calibrate mercury based thermometers. He came up with a third reference point: the temperature you get when you insert a thermometer into your mouth. This was originally supposed to be 90 degrees. Later it was determined to be 96 and we now know it is 98.2 degrees. In other words, he kind of messed up there by picking something a bit harder to measure.
The final reference point that Daniel Fahrenheit worked with was the boiling point of mercury. Which he put at 300 degrees. The scale was redefined several times according to progressive insights regarding e.g. the notion that there are about 180 degrees Fahrenheit difference between freezing and boiling water.
The latter is of course an attempt to reconcile the scale with the centigrade scale which is based on the freezing and boiling temperatures of water. That's technically also somewhat imprecise of course but quite easy to figure out. Basically take water, put ice in it, wait a bit. That's your zero point. Then put it on a fire, wait for it to boil. That's 100. Put two little markings on your glass tube with mercury where that happens and then divide that into tens and again into tens. That's a repeatable process for making a thermometer. Not super precise of course because it depends on air pressure (later of course factored into its definition). But if you are making thermometers, that's pretty easy to do if you are an eighteenth century instrument maker. You need ice of course but that would have been a commodity much of the year where Celsius was living (Stockholm).
For better or worse, the metric system actually uses Kelvin which simply is the Celsius scaling (or centigrade as it was called originally) but adjusted to absolute zero −273.15°. That last adjustment by .15 degrees happened only fairly recently actually. Fahrenheit only continues to exist as a derived scale from that. None of its original reference points are precise enough to matter these days. That's true for most remaining imperial measurements: they are defined very precisely in metric units. You can measure feet with your feet of course. But only if you don't care about precision. Any self respecting engineer uses more carefully calibrated instruments.