I think a lot of commenters here are missing the point and getting distracted by push notifications (who wants a website spamming them with notifications?) and loading screens (hardly a feature). Apple supporting PWA (Progressive Web Apps) is hugely important because it enables a future where web apps can natively support browser, Mac/Windows/Linux desktop, and mobile iPhone/Android/Windows native mobile with a singl…
It's a sad state of affairs for the web when we see articles claiming that one company's failure to adopt a standard amounts to threatening the web. The open web supports and should encourage competition, not blind homogeny.
I don't think it's misguided for a company to hesitate in supporting a platform which will enable its users to jump ship to another competing company.