I've seen this before....its a wet bathroom, which means it's water sealed with sealed electrical outlets and extra drainage. You can take a hose to the entire bathroom to clean it. That's why there's no shower curtain, since it isn't needed. It's kinda overboard, but people with money seem to like them.
I don't really see it as overboard. People in Japan (and elsewhere) have wet rooms. I'm a fan of them, cleaning is easier and additional protection from flooding. It's the exact opposite of carpet in the bathroom.
Whole place has weird 70's Rec Center vibes. Retro horror flick waiting to happen. Cleaning would have to be done with a small pressure washer, way too many crevices/rough surfaces.