iOS users are known to pay for apps they like. Android users less so.
In the end it is a choice of business model. Taking the risk of making money while being dependant on one party (Apple, Youtube) is always a huge risk.
Edit: Just to clarify I'm not bashing PWAs I've developed a lot for both the web and iOS and consider myself fairly mercenary, I will jump ship to other tech if need be. But there is still quite a way to go[0] and it's going to be hard to get these companies to agree on some of these standards. I'm also conscious of the fact that PWAs may just replace one dictator (Apple) with another (Google).
I don't even want to make any money off iOS apps in the short or medium term. I just want to make apps for my friends and family, and have the iPhone users have as good an experience as the Android users. But I'm not going to get into iOS development just for that. Why, why, why can't I just achieve it with a PWA?!
Because Apple will make less money that way, that's why. Again, it makes sense, but I still hate them for it.
