I'm not the person you are asking but I'll lay out how I understand this argument from what I've read about the housing market in Portland, OR, which has a big housing crisis right now.

Available housing, apartments, condos, etc, is being eaten up by short-term renters. The price of short-term rentals are more expensive than long-term rentals, but due to so much inventory not being free for long-term rentals, the price for long-term rentals has gone up a lot. This is the same inflation that we see in the expected vacation destinations but in non-traditional locations, like Portland and it's suburbs.

AirBnB is supposedly built to empower individuals to post a rental here or there. What has been found is that it has enabled and encouraged individuals and companies with large inventories to convert long-term rentals into short-term ones. And that 15% that AirBnB takes is simply passed onto the consumer - which then affects the price of long-term rentals.