A true cross-platform Edge (Android/Linux/Windows) would be a real plus.
I use Windows and Linux on different computers, and Android on tablets. I've kept dual browsers (Edge and Firefox) on my Windows computers, but use Firefox as my default browser (that is, the browser I use for legal/technical work and the browser on which I keep my Bookmarks/Favorites) because Firefox offers Windows/Linux/Android support.
I like Edge (Classic) a lot, and I have used it daily for casual/recreational browsing since Windows 10 was introduced. Edge Chromium shows tremendous promise, and I intend to use Edge Chromium for that purpose going forward. But I need to be able to use my legal/technical Bookmarks/Favorites cross-platform, and I will keep Firefox as my default for work until Edge Chromium is ported over to Linux as a Snap or Flatpak.
MS seems to be moving in the direction of offering meaningful support for Linux in many areas, so it would be a logical step to take for MS to port Edge Chromium to Linux.
We'll have to see what happens, but I hope that this is the direction in which MS is moving on Edge Chromium.