"It is a stinky bacteria infection in the armpits. "

If it is a infection, then something is very wrong.

Otherwise you can and should clean them with care, especially when you cannot shower.

In summer: you need a shower to wash the sweat off

In winter: you need a bath to get as warm as possible before going to bed. Until recently (~1980s-90s) houses were expected to be ephemeral, whether they were knocked over by an earthquake or the new owner, so people skipped "luxuries" like insulation.

> washing your skin with just water is good for it if not outright neutral

Not true, excessive washing even just with water dries your skin plus not everyone has exactly pH neutral showering water. So yes, you can wash every day and then apply lotion/cream or you can just not wash and avoid all of that.

Not only from just existing, but between going to the gym a few days a week and doing regular cardio on other days, I just can’t imagine the absolute rank stink from not showering regularly. Once I thought I didn’t work up enough of a sweat weightlifting in the gym so went to bed when I got home, and the bed smelled like absolute trash the next day and neither me nor my partner could sleep there again without washing everything.

Maybe it’s just my neuroses or mental illness, but I can’t imagine smelling so badly and not showering even if I didn’t socialize with others, and can’t imagine I’d have many people to continue to socialize with (in USA so this is probably different in the OP’s country) if I smelled so bad when I went out.

You smell bad because of your diet.

Build up of aromatics in your adipose tissue that are released over time via your sebaceous glands, bacterial decomposition products of those compounds, and off-gassing of bacterial decomposition byproducts from your orifices contribute to bad body odor.

People are different and skin biomes can change. The ways that showering habits (frequency, duration, temp, ph, soap use, etc) effect skin biomes is poorly understood. The largest factor in body odor is the bacteria living on our skin, so it is entirely conceivable that with a different showering regime your skin biome would change over time and cause you to generate BO differently.

What fraction of people do any substantial physical work in an average day? I reckon about 25%.

Hackernews told me that this is just another microbiome that needs to be brought into balance, after which the smell goes away; and that soaps and shampoos disrupt that balance.

As one who's hung out with bohemian vagabonds who didn't make a routine habit of bathing, my nose has told me otherwise.

Nice people but... humans smell funny in general.

It's really not that simple. The bacteria that live on my skin don't stink like that after a lot of exercise.

Fun fact- most Koreans don't have the same sweat gland that many others have that produce the type of sweet that the stinky bacteria feed on, and thus don't stink like Americans from sweating (they do have their own smell, from what I understand, but it isn't as pungent) and thus they don't usually use deodorant/antiperspirant. It is my understanding some other Asian groups don't stink or don't stink as much, as well, due to differences in the sweat produced.

OP is confusing overall use which includes agricultural and industrial use with municipal use.

It doesn't really matter, ebcause it applies same to all countries, so it doesn't explain why Americans need to consume 4 times more water per capita (3794 litres) than Germans (855), while Czechs for instance even half of the Germans (422).

And don't go at me with average temperatures nonsense, Spain and Greece are warmer than most of the US and have half of US water consumption, Thailand little bit over half, Malaysia less than 1/3 of US consumption.

Last time I checked US was not a tropical country. Obviously when I travelled around Southeast Asia I was showering daily. We are talking here about your regular American living and working in AC home and moving between them in AC car and shopping in AC shops and not doing manual labor.

> Locals don't have this problem.

Oh they do, but for instance they use prickly heat powder in some of those tropical countries. And that's also reason why everything is airconditioned and you freeze in buses, cinemas, etc. so they are comfortable and don't sweat that much.

US water consumption per capita is 4X higher (3794 litres) than Germany (855), 9X highter than Czechia (422).

Even warm Spain and Greece have half of US water consumption, Thailand little bit over half, Malaysia less than 1/3 of US consumption, so there is no reasonable excuse why Americans waste that much water.

I take several showers /day in summer but they are usually quick 1 minute rinse to cool and remove sweat. Only one is done with soap.

Some people would probably use more water in one 10 minute hot shower / day. Never understood people taking long showers.