It just highlights that the whole process is awkward security theater. The only security is Moz being able to revoke access.

That is basically the whole purpose of that. A kill switch used when everything is on fire. Allows them to deactivate wide spread malwares when they discovered it. Although I have no idea whether it works or it is ever being used.

On the other side. The chrome store starts to behave badly and ban extensions they don't like for random reason after they implement that.

About mozilla, i don't know. will they eventually be like that, or they won't?

Or just use the developer edition and enable unsigned extensions.

Developer edition is a beta (or alpha since it derived from aurora line which came from alpha). You can say it doesn't have bugs but it has more than release editions. In my experience many more. Using a beta as a daily driver is not something to recommend.

Now, some distros like Debian have enough political power to get Mozilla to allow them to put Firefox branding on their altered user-freedoms-respecting repo editions of FF release. But most don't. So the only way to use actual release FF is to go outside your repos and use the unbranded version. Possible, of course, but tedious.

Even the nightly is actually quite stable in my opinion. I already used Firefox Nightly daily for years. And don't encounter major usability problems(startup crash, page not rendering type problems). Although it do sometimes have minor problems.

You can enable developer mode on release Chrome (or Edge Chromium, which is what I recommend) and use any extension you wish directly by loading the unpacked source directory.

That results in a big giant warning you have to dismiss every time when you start the chrome. Although that isn't avaiable on release channel branded firefox anyway.