you can install firefox, but even if you click 'make firefox my default browser', it won't. It will open the settings, wait a second and then show you another button. Clicking that will do what you wanted - for web links. Pdf files? Html files? Searches from the start menu? Still all open edge.

On ubuntu it takes maybe a minute to remove the firefox snap, add the mozilla repo and install from there. Those dummie packages are more for convenience than anything nefarious. I agree that snaps have been made unavoidable if you're not paying attention, but I disagree that it's a bad thing. Ubuntu is migrating from .debs to snaps, so it makes sense that those become ever more prominant.