Nah I refuse to accept its for efficiency or cost savings. Thats so negligible no one would bring it up. Especially at the scale these are being constructed.

Ive seen a ton of arguments like “oh its to save costs installing if the floor is uneven” or “it gives leeway for different cuts” or “its for cleaning” but these are things can can easily be designed around without having a gap that leaves the user exposed. Either Americans are to stupid to design around this constraint (they aren’t) or theyre intentionally leaving it in for some reasons and there is plenty of speculation on the reasons.