Yeah, but you won't build a business on that, you'll add GPS trackers, make renters show you their drivers licenses etc. A captcha isn't "wrong" in general in my mind, it's just not something you add and you're all done, and it shouldn't be your first line of defense. It can be part of a multi-pronged anti-abuse strategy, but it's a very tricky part: it doesn't offer a lot of protection but creates a lot of friction for actual, legit users. Running a DNA test on somebody can be a good way to verify their identity. But asking for their ID card and looking at the picture is a lot quicker, cheaper and less intrusive.

I don't see captchas a lot, because I'm not frequenting sites that use them. A friend of mine apparently does, so often that he pays for a captcha solver while he's sitting in front of his computer. He just can't be bothered to play Google's mind games, so he'd rather pay a few cents a day to not deal with it.

We've come to the point where humans are paying for services that were created for bots so they can bypass technological hurdles that were meant to tell humans from bots.