yes but in a shower your only contact with a surface is the sole of your feet, easily covered with flip flops (this is why I said gravity was my friend)

In this you are literally seating naked where someone else sat naked. I am sure they'll sanitize it but I just would hate it.

I am certain the end game for this one is to assist people with disabilities or the elderly though which is certainly more dignified than being washed like a dog at the groomers

Not likely in Japan.

That's what the waffle stomp is for.