I know a guy who went to a party in high school at this girl's house and her dad was one of this guy's teachers. They had a hot tub and he railed his GF in there, but pulled out, which is repugnant but he thought it was pretty funny at the time because he disliked that teacher, and, was bitter that he wasn't railing the daughter because she had cans from the hands of God and her boyfriend was this wannabe coke dealer loser.
Anyway - no shit - this guy's GF actually ended up getting preggers. But it wasn't likely from the hot tub seahorses... Probably.
*This reckless escapade was before CoVid.
But yeah, hot tubs make sense for those who use them 5x per week and for no one else. I bet that's only 3% of owners, but this will turn into a motorcycle mileage debate, so obviously everyone totes uses them. My neighbour has not been in theirs even once for over 60 days.
My electrician acquaintance says that "install is $1k" IF you put it in your basement, literally next to the breaker panel. Otherwise, he hasn't installed one that was under $2k. I believe the daily heating cost is slightly over $2.
I really enjoy them when I'm on vacation, but know I wouldn't get proper use out of a personal one so it's not on my radar.