Vacation rentals are just as far from what AirBnB (originally) offered as a B&B. Usually handled by a property manager, entire home, nice location / popular holiday destinations and facilities as it is someone's second property. Much higher prices. This is a far cry from an "air bed" in a corner of a standard urban family apartment in São Paulo, which you'd find by the thousands in the early years before regulations caught up.

I think you're underestimating how much AirBnB as a platform opened up this market to the average traveller, including business travel, and yes, absolutely contributed to the housing crisis, though I wasn't even making a point about that.