I've talked with elderly blue collar working class Australian's who've encountered { bidet's | jet washing arses } for the first time .. once they've used them they almost all 100% don't need convincing that they're desirable.

It's literally an ad campaign | marketing problem .. and given how popular pressure washing youtube videos are, there's one angle to work from :-)

Probably Italy. From my experience in the Netherlands, a bidet is quite rare and requires a new toilet in some cases as exposed plumbing went out of fashion 20 years ago so a retrofit is not easy like with most North American toilets.

In Poland it's rare, but it's there. I have one and my last two summer vacation stay places had them.

Up until a couple of years ago you were not legally allowed to build a house without at least one bathroom with a bidet, so essentially all houses built in the past 80 years in the country have bidets

I grew up in France, every house had one.

Italy has bidet in every bathroom