If an update causes me any problem, I can reboot to a snapshot (3 hourly, 3 daily, 1 weekly) and if it's an issue with my Firefox profile folder, I would just copy back one of the rsync backups:
I have the benefit of experience, I loved my Nokia 3210, bought a Nokia 3310 - but managed to lose it a few years later... and was shocked because I had no record of contacts/phone numbers.
With Firefox, I learned that trying out a new version could 'update' the profile, and then reinstalling the old one wouldn't work with that profile (I had to use sync to restore it). Since then, I always have a snapshot of the entire system, plus regular backups to defend against hardware failure.
Some people believe in Evolution, they think that the world would move forwards...
These days it's so trivial that it's hard to estimate the intelligence of anyone who doesn't do it, and then complains that something went wrong.