Japanese-style washlets are pretty uncommon outside of Japan generally. It's not an America thing. It does cost a fair bit of money to do an install (plumbing/electricity) if you're not having a major bathroom renovation anyway, given the average American hasn't been to Japan they're mostly not familiar with the concept, and just general reluctance to talk or think too much about toilet design.
I have one so I'm not talking about myself. But it seems to have long not to made it onto US radars as something you should have even in a high-end bathroom.
You don't need warm water / electricity - you get completely used to the water temp after using a week or so. The bidets on Amazon (pretty cheap) work just fine and install onto most toilets in 10 minutes. Super easy and affordable.
I have one so I'm not talking about myself. But it seems to have long not to made it onto US radars as something you should have even in a high-end bathroom.