Depends upon where you go in South Asia, there are no seats because you don’t sit to do your business, you squat.
This goes for many parts of Southeast and East Asia, too.
You might have noticed that people do a lot of “hunkering down” there.
Other places don’t have the knees for it, anymore.

I never sit on a public toilet or even another person's John but it's nice when the seat prevents the splash.

On a side note the toilets that use less water are hilarious. You end up flushing multiple times just to make the matter disappear.