They have nearly impossible to solve maintenance issues unless you use special chemicals and maintenance procedures, and unless you wash/flush them (and the surroundings) regularly the urine smell is hard to deal with.

Since most maintenance staff don’t do the special procedures properly (and barely manage to deal with normal toilets properly!) they were a big headache. [https://www.waterless.com/blog/the-pros-and-cons-of-selectin...].

Everywhere I know of that was using them eventually got rid of them because they weren’t worth it for the small water savings they actually got.

Especially since water usage was never anything but a hot button PR topic - there are probably only a handful of places humans habitate that the difference is actually non-negligible when you factor in showers, landscaping, etc.