@Lisa723
Perhaps that's true. Restricting on the basis of age is very common here. Fir example, you generally can't rent a car if you're under 25, unless you out down thousands in deposits. Your insurance premiums will be much higher if you're under 25.
Most villas in our area won't accept under 25s as a group. Except on Airbnb of course, since there's no filter for that. And I know of at least 3 villa owners who refuse to use Airbnb for that and other reasons. They've successfully long established themselves on other platforms and have no motivation to list on Airbnb.
Although I maintain that Airbnb if nothing else, delivers bookings. It's really good at that. Nowadays, you just have to look very carefully at who's booking. It requires somewhat skilled work to avoid scaring away the good ones in the process, but Airbnb can be very rewarding ...if you pay attention.