I wouldn't underestimate it, but comparing the balance sheet of Booking.com and airbnb you see that booking is crushing it and Airbnb in an overvalued company (with meh growth.

Last quarter for example, Airbnb had timid growth, meanwhile Booking did much better.

For the current size Airbnb is (not as big as Booking.com), and market valuation, I'd have much higher expectations for it.