Internet Explorer 9 does support HTML5. <Missing feature name> are not supported, but HTML5 is more than <missing feature name>.
Let's not mince words now. Apple purposefully cripples Safari to make native apps more competitive because they get a cut of every sale and it boosts their claims about the AppStore too.
Mincing words is claiming that iOS does not support PWAs. That's false. iOS support for PWAs is worse than Android, that's true. Whether that's because of AppStore or not, one can only speculate, but it might be true. Still there are plenty of useful APIs supported on Safari, there is dedicated support for PWAs, there's dedicated support for creating home screen icons. That's enough for many web apps.
