As exposed in the recent indictment, their analytics submits everything you do in Edge with your unique ID to them, so they can track every site you visit and everything you do on them, down to hotel reservations.

Windows and everything else Microsoft ships is just a way to get better targeting data for ads.

It’s not about the underlying technology, it’s about all the stuff that comes with it.

If you’re pushed to use Edge your default search engine is now Bing, which means ad revenue for Microsoft, and things like idle news browsing being sent over to MSN.

Like the other commenter said, Microsoft has zero care for technological supremacy, or even just pushing out a good product. What they do care about is all the useful telemetry data and other signals that get generated inside a browser that they now have access to. Heck, they don't even have to pay to continue supporting the underlying browser technology like they did when they were competing using Internet Explorer.