I did search a bit to see how widespread the issue with Booking.com and similar was, and while the numbers at first seemed pretty large, when compared to the total number of bookings they aren’t as horrible as some may think, Still, the better answer would be zero.
I view the core flaw of the "platform economy" is that aggregators
exist purely to insert themselves into a transaction, siphoning off
money while listing someone else's property - which may or may not
even exist - without offering a single piece of physical inventory of
their own.
Unless you are a small business that would not be able to exist without the aggregator’s marketing and payment collection resources. Which is why aggregators like Viator and GetYourGuide do so well. They facilitate the development of businesses that otherwise would not be able to exist.
It really calls for adding regulations to internet marketing, in my
opinion. Until that happens, it's going to continue. Google supposedly
monitors it, and you can report the "sponsored" companies online, but
I don't think anything gets done.
What is going to continue? Being listed by and using aggregators is voluntary. Anyone that doesn’t like one end or the other end of that equation is free to do so. I would rather not have a government telling me where I can advertise and where I can purchase. I know it sounds good, but look at who runs government and ask, do I really want them making the decisions that regulate all my little life decisions? There are only two things that a government can do better than an individual; collect taxes and fight wars.
Hacking into a platform to steal credit card numbers or rent non-existent property is already a crime. I am game for holding the platform responsible for compensatory damages when it occurs and punitive damages if they cannot demonstrate that used reasonable care in protecting the client. I think the laws may already provide for that, maybe we just need a case or two to establish the precedent. Of course nothing in life is free so the more you regulate and punish the more expensive that hotel room will be.