One particular concern that always comes to mind for me, because I use Web Components at work, is that we would have gotten a much worse version of Web Components if not for Mozilla's opposition. That sort of opposition isn't possible from the vendor of a Chromium-fork.
They don't. They are still publicly opposed to the most egregious Google "standards." See https://mozilla.github.io/standards-positions/
One particular concern that always comes to mind for me, because I use Web Components at work, is that we would have gotten a much worse version of Web Components if not for Mozilla's opposition. That sort of opposition isn't possible from the vendor of a Chromium-fork.