Whatever they manage to eek out in the EU, is the future of what iOS will be in the US and worldwide eventually. If they go with fully fledged PWAs that the other browser engines will enable - there’s little reason to use the Appstore, hence Apple losing their 30% commission.
From their perspective it’s not so much throwing a tantrum but clawing and screaming their way into giving up as little revenue as possible.
And as a developer, I see how I'm going to be collateral damage, and am less likely to do anything that gives Apple more power over me and my customers. If that means a bookmarked web app, so be it.
We also know 70% of revenue comes from games. And there's no way proper game is going run on a PWA.
I also invoke Android again... PWAs exist, Google still holds the lions share. Google has freaked out about it too and is being sanctioned as we speak for it, but most customers simply aren't going to look for an alt app store outside of niche uses.
In particular, all game streaming services (Geforce Now, Xbox Game Pass etc.) have until very recently needed to exist as PWAs since Apple would not let them into the App Store.
The crucial PWA feature here is being able to display them in full screen, without Safari's navigation bar.
From their perspective it’s not so much throwing a tantrum but clawing and screaming their way into giving up as little revenue as possible.