I would assume any grower going for high pecentages in tests are going to pick the biggest choicest top buds to have tested.
Meanwhile, you buy some of that weed from the store and you may end up with some lower buds that barely got any light, or some that was in the back corner of the room while drying and didn't finish properly, or that bud the workers kept brushing against while it was growing knocking crystals and resin off, or maybe the grower sold it before curing properly to make a quick buck so every seller that ends up with it ends up either curing it themselves in different ways or just not bothering at all and selling it as is. The seller may just sit on it for a while and let it degrade.
All of those factors, and many more, have an affect on the amount of cannibinoids and terpenes in any specific bud you might end up with.
Just because a specific strain or even crop was tested as one thing doesn't mean the weed you actually buy will be that.
Concentrates tend to have less variation within one batch, but that again depends on how their made.
A lot of it in the end is just marketing. Even most strains you buy are likely not what they're sold as. Even if a grower is able to maintain a stable line, over time after successive generations of clones, genetic defects and other undesirable things begin to occur and the grower needs to introduce fresh genetics, thereby changing the original strain.
Cannabis genetics, breeding and growing is a pretty fascinating subject. There's so many factors that go into the final product and just so much variation and endless new discoveries every day.
One could also eat half of a 1mg edible, which provides even more precision dosage.
I know of only a few vendors that sell "medium" flower - and retailers only let them in because they have some hi-test product too.
In any case, thank you, it's nice to know I'm not the only one.
Their menu lists 9 CBD flower products and 97 CBD edible products, not to mention topicals, concentrates, etc...
The product I wish I could find is very rare, I've almost never found it. Something more akin to the "dirt weed" I grew up with, THC around 4-5%. There just isn't enough of a market for "I want to get a little high". There's a high THC market, and a high CBD market, with not much in between.