2.5 to 3% according to google... Small but not tiny tiny
Some people just live in places that aren't suitable for human life and survive only through technology. Those places need to have different laws about water.
For example, I shouldn't be forced to use a low flow showerhead when I'm 100 miles from 1.3 quadrillion gallons of fresh water. If you aren't next door to lake Michigan then maybe you should be.
Also, it's not 3% of 2/3. It's more like ~1% of 3% of 2/3. Most of the fresh water on earth is locked up in glaciers or trapped deep underground. You can absolutely lose surface water, too - when pipes leak, for instance. And that happens all the time because a lot of the water infrastructure is ancient. Where I live, there are still thousands of miles of Victorian-era pipes. These crack all the time. You don't just get that water back straight away when it next rains.
Where the heck does it go? Space? You're talking about the entire planet here. There's nowhere for it to be lost to, unless you're cracking it into hydrogen and oxygen or something.
> Because you're the only person on earth who matters, clearly.
As I said elsewhere in this third 2/3rds of humans live near large bodies of water.
Maybe if you live in a desert. I'm not going to. We don't all live in the same place, and different rules are necessary. I suspect that much of the talk about evaporative cooling comes from treating places where it is sensible to do as if they are places where it's not.
There is a lake not far from that it would take about 3 days to cross on foot at it's SHORTEST point. Walking the full length would take about TWO WEEKS, someone would probably die of dysentery along the way.
Water scarcity is a regional problem that's being passed off as a universal concern for all of human-kind. It isn't. Earth has water, lots of it. Some places are just crummy places for humans to live.