Earlier quoted context omitted.
Depends on the vertical. I would not be real comfortable booking lodging on some random portal, especially if we're talking more of an AirBnB thing vs hotels.
Yeah, that's one of the moats some have but booking.com has not: you don't just pop up a hotel from nothing, and the hypothetical failure mode of complete fakes appearing out of thin air is not only solved by payment on site but also by the local hotel owner community having a financial interest in policing their turf. Or not, could be a fun plot for some speculative fiction: on a cooperative post-booking.com platfor…
That + trust + customer support at least for me is worth more than at most 5-10% you could save.