It's the same reason Coinbase, Square, Stripe, Airbnb (among many others) are worth what they are (ie rich multiples on sales). Their domains are extraordinarily difficult to do very well and now that large competitors are in place (in those segments) it's borderline impossible to take a big chunk of the market away from them. They're entrenched, potential future monopolist tech monsters.
The market loves these types of stories, right up until the growth inevitably declines to/near single digits and then they get a boring eBay valuation (circa ~2003-2019).
The short of it is, a lot of the future returns have been pulled forward.