You’re conflating lots of unrelated things. IE was a horrible browser to support because Microsoft deliberately implemented their own incompatible version of web standards, or refused to implement modern standards. The push to deprecate IE was because it was creating a massive burden, I personally dealt with IE6 support in corporate world and can attest it’s depreciation was necessary.
What you call chrome skins isn’t a thing, people are building softwares on top of Blink, the rendering engine used by Chrome. The issue here is the risk of ending with a single rendering engine for the majority of the browser market, a diversity of engine ensure a good respect of web standards, that has nothing to do with privacy or security.
When you say “they just replaced IE”, that was >10 years ago…
