Completely the opposite for me. At least booking.com allows reviews only when you booked. And when I read the comments most point out real problems or benefits

Completely the opposite for me. At least booking.com allows reviews only when you booked. And when I read the comments most point out real problems or benefits of the different housings. AirBNB reviews on the other hand are painfully useless. And Google is the worst, with a shitload of review from people that look like that probably didn't even went to the place, or just disliked being denied on a discount of something, so you jget useless 5 stars review that say "best food ever" and 1 star reviews for "super rude server, worst restaurant ever" for the same average restaurant, and nothing in between to tell you what the place actually feels like or what food is good/bad there.