This house is really amazing, but this bathroom is a little much: https://www.oldhousedreams.com/2012/03/29/1960-lambertville-nj/ (Last sold in 2015 for $630K: https://www.longandfoster.com/homes-for-sale/315-Goat-Hill-Road-Lambertville-NJ-08530-250220020)
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.
I’ve never seen one with this texture before. It’s always been tiles when I saw them.