Most of the revenue made from app stores come from pay to win games (which need native performance) or subscriptions that work across platforms. Many major players that use subscription prices have abandoned Apple’s subscription payments.

Second issue, what are the chances that I would trust some random website with my credit card information?

Except that those PWAs are not making money to get a cut from anyway. Or if they do it's via ads which makes them non-starters anyway.

^ exactly and when there are big benefits to developers like that and the technology is focused on more, the maturity of what it will become is what really excites me