On the contrary, they kill your knees. Sure one can feel nice about them in their youth, but it is pretty hard to use squat toilets in and after your late 60s.
A full deep squat doesn't put the knee under as much tension as doing a half squat (or perpendicular squat).
My grandfather whom died in a car accident was 98 and would be squatting down in his garden. My father does with his dog at 76 just this past Sunday.
It really isn’t a problem later in the families I’ve seen unless some sort of disability occurs. In those cases just like all we adapt.
Heels flat on the floor, knees in line with your toes, but behind them. If you don't have the hip mobility you need to get your knees behind your toes, you'll feel a strain on your knee.
You should be able to lift your toes off the floor as you stand up - all the weight is on your heels.
Specifically, "after your late 60s": are you talking about people who don't squat ever, and then try to in their late 60s? Or are you talking about people who squat regularly and find themselves unable to squat after 60?
If the latter, I find it hard to believe but I am open to citations.
Regarding squat toilets, their biggest benefit IMO is hygiene - your skin never touches anything.
Contrast this with a sitter, where even the 'clean' ones require contact with your skin.
I'd take the squatter every time, thanks.