>What’s stopping google from doing what they did with Android: remove more and more and more of the parts included with open source Android and move them into closed source Android to the point where vanilla open source Android has much lower utility?

Microsoft has more than enough resources and engineers to continue to support or even fork Blink even if Google went full closed source (just like Google did back in the day with webkit).

I wouldn't trust Microsoft to be better than Google on privacy TBH. In fact I feel that given the opportunity Microsoft has prooven time and time again they would be worse, but they aren't as successfull with Bing so they don't have the opportunity.

Google can’t go closed source with WebKit because it is LGPL software not originally written by Google.

WebKit came from the KDE project via Apple to Google.

The answer is nothing, but then again there's very little stopping your neighbour physically from murdering you in your sleep too. Perhaps this is not something to worry about, or perhaps it is! The way to figure out whether or not that is the case is to reason a little deeper than "well it's possible", which is true for far too many things to be useful.

> What’s stopping google from doing what they did with Android: remove more and more and more of the parts included with open source Android and move them into closed source Android to the point where vanilla open source Android has much lower utility?

This is somewhat explored territory. KHTML, Webkit, Blink etc. have resulted in a lot of the "important bits" being in WebkitCore.

Yes. the latest edge is a chromium fork, and there is bidirectional development/patches being submitted by MS. I've heard anecdotally that much of MS' effort has been in de-googling chrome, but given MS history, it is probably being replaced with their own telemetry, with the added bonus of integrating their telemetry on the OS level as well.