Our showers are seperated from the bathroom floor by at least a few inches of lip (for lack of a better word) so that water never flows into the rest of the bathroom floor. The drain is only in the shower section, so you can’t spray down the rest of the bathroom with water and have it just drain out.

A drain in the bathroom floor (rather than just the shower floor) allows you to spray water on any of your bathroom walls, appliances, and fixtures for cleaning and it will just drain away as if you were running the shower. We generally can’t do that here in the states.