There is a lot of precedence that Apple is very reluctant to implement web-app standards, that could compete with the app store.
For some opinion pieces you can search for "Safari is the new Internet Explore"
For some opinion pieces you can search for "Safari is the new Internet Explore"
It is whispering to a very specific audience.
And through all of this, the most remarkable thing is that Safari is hugely over represented among web visitors, both from iOS and Macs. It's almost like providing an extremely fast, light, energy efficient, feature rich browser encourages its use.