It’s a smart design even if it’s not used for handicapped people.
(a) you can wash the bathroom floor easily.
(b) if water splashes beyond the curtain or enclosure, you don’t get water dripping through the downstairs ceiling since the whole 9 yards is sealed
(c) you can change the shower configuration as much as you like without doing much remodeling
Don’t know why all new bathrooms aren’t set up that way — for new construction or a gut renovation, the additional expense is approximately zero.
As an aside, when I traveled in Japan, I encountered a couple homes/apartments where the shower was an entirely separate wet room, accessible from the rest of the house rather than from the bathroom. Smart design — keeps the moisture away from everything else, and allows one person to use the terlit while the other showers. Also would get warm very quickly once water starts running.
