Some of the things that have already been mentioned are true also for me, especially around permissions and assumptions about my system's setup. However what really did it for me was when Firefox stopped recognizing my keyboard after a snap refresh. It's just as if no input device was there for FF anymore. I found reports of the issue, but no solution. In the end I installed from a DEB repository and went through the shenanigans to prevent snap from reinstalling it.
Some of the things that have already been mentioned are true also for me, especially around permissions and assumptions about my system's setup. However what really did it for me was when Firefox stopped recognizing my keyboard after a snap refresh. It's just as if no input device was there for FF anymore. I found reports of the issue, but no solution. In the end I installed from a DEB repository and went through the shenanigans to prevent snap from reinstalling it.