Given that it uses Chrome's engine, Edge isn't an alternative to Chrome. It's just an alternative version of Chrome.
Sure, from a user perspective, it's an alternative. From a dev perspective, it adds to the dominance of Chrome.
M$ is very clever.
Bill-Bashing can stay buried now that he has moved on to charity, though.
I am hoping/wishing that Mozilla will drop gecko development and repackage WebKit - it would be great for them to join forces and pool resources with the #2 engine!
But let's assume they switch to Webkit. In itself that is a huge investment. Then either they track whatever Google wants to do with Webkit, or they fork. But once they fork, they're pretty much on their own again. So there was no gain. To profit from Google's dev, they have to track whatever Google does, and maintain patches for their own things that Google doesn't want to merge. In some important ways, they'd be dependent on Google. Their direct competitor.