Please talk to any frontend developer active in the days when Internet Explorer was king of the hill because they will debunk your entire argument.

Internet Explorer was the one being shit. And Microsoft could get away with it because they literally destroyed Netscape by including this shit browser with the OS.

The only event improving things was that out of the Netscape wreckage Mozilla emerged which gained so much market share with Seamonkey and Firefox Microsoft just had to pay attention to W3C specs again.

So Mozilla basically was the only reason Internet Explorer 9 and 10 were less shit than their predecessors.