This is overbroad.

Many people are acclimated to low levels of dehydration and do not feel thirsty when they should.

Setting an imprecise, but safe, target number is helpful.

people who are actually experts in kidneys and how the body manages water disagree with you. they say thirst is a fine way to go with exceptions being very rare and mostly among the elderly, but that even there 8 glasses of water a day is way more than is necessary. as well the idea that coffee/milk/juice don’t count is also untrue.

I've noticed that I drink a ton more water when I have my water bottle on my desk---I rarely get up to go get myself a drink (because I'm deep in whatever work I'm doing), so I would wait too long without the water bottle. The convenience factor certainly plays a role in determining what the "thirstiness threshold" is.

but is it doing you any good? are just drinking more often but smaller amounts? is it just nice to drink but not useful?

> are just drinking more often but smaller amounts?

Probably. I don't measure my water consumption, but I'm guessing that I drink smaller amounts. Even if my average hydration level is the same, it never goes too low this way, which means that I feel better.

I don't have any objective way to measure the health benefits of drinking a certain amount of water, but it definitely makes me feel better to be more hydrated, so I'm guessing it's good for my health.

When it comes to physical activity (sports, weight lifting), I have read that muscle performance can be greatly impacted by inadequate hydration. So while you may not feel thirsty, you could be forcing yourself to work harder than normal simply because your body is not operating efficiently.

> There is literally no evidence that humans need any "goal" when it comes to drinking water, just drink when you're thirsty.

Actually... there is. You should stay below 1lt/hour on average because that's about the limit your kidneys can handle.

The trouble is so many people have no idea what it means to be thirsty or hungry. Or they don't think they could be bothered to drink plain water, and instead only drink sugar all day.

"Drink water" is a radical idea for a lot of people.