I’m actually kind of sad about this because it risks turning the Web into a monoculture again. Even if it does have the potential of making it substantially easier to build and maintain web sites in the long run.
On the other hand, I’ve been using Firefox on Windows because Chrome tends to drain my batter faster than Edge and like the extensions available for it. But having Edge on the Mac with a Chromium engine would make it easier to keep my bookmarks synced across platforms…
As lean and mean as Safari is these days, however, I find it has niggling issues with cookie session management and odd corner cases on mobile, and there is already ample talk about it being left behind.
Your move, Apple.