IE6 was stagnant and not standards compliant. Safari at least complies with standards. Chrome is the polar opposite of IE6. Turns out it doesn't really matter what you do, if one party controls too much of any market it's bad news for end users one way or another.

Maybe because Safari isnt funded by Apple, and would rather pump that money into extracting rent from App Store?

The few engineers that Safari has are top-top notch, but they wouldnt let them grow the teams and would much rather drag their feet.