I run rentals on airbnb in a major city catering towards business travel. I've never had anyone try to extend directly. I set up my own site to market independently. I put my prices 33% lower than airbnb prices, even though they only charge low single digit fees.more than 99% of my bookings come through them, even at the higher price point.
Also, a significant percentage of my customers are staying for the first time on airbnb. They are growing very quickly, and their operating leverage is likely very high. I've interacted with them only a few times and paid many thousands in fees.
Other factors: they are adding more tools for professional hosts. Their previous UI was very cludgy for managing multiple properties. Now it is much better, which should allow them to take market share in independent property managers, which is a big market in vacation areas.
I received a survey from them awhile back asking whether I'd be interested in getting an advance on my payments (paid prior to check-in) for a discount. This would essentially be a factoring arrangement. I said no, as their proposed pricing tiers were very, very high (20%+ effective rates).
However, running a hosting business eats working capital, and doesn't necessarily attract financially sophisticated people. I think there is a very good chance they will be able to deploy a few billion in float at double digit returns on that.
Similar experience when I was a host. If I had to guess, maybe 80% were first time users. But this was back in 2010 - 2015.