You should back up the settings for your Firefox addons periodically
Today I had some unexpected excitement with two of my core Firefox addons in my core browser, where either or both of uBlock Origin and uMatrix apparently stopped working and stopped everything else from working along with them, since they're on the critical path for getting web pages. I eventually got everything working again, but I wound up needing to remove and then reinstall from scratch uBlock Origin and uMatrix, both of which have complex configurations. This is where I discovered that my most recent backups of those settings were from 2020 (and from a different machine). Oops.
(I have full filesystem backups, but as far as I know you can't easily extract an addon's settings from a Firefox profile directory, so I would have had to completely restore my entire Firefox profile.)
Many of my Firefox addons have some sort of configuration settings, and yours probably do too (if you use addons). uMatrix and uBlock Origin have a collection of filtering settings, Foxy Gestures has my gesture customizations, Stylus has a bunch of styles, Cookie AutoDelete knows which cookies I don't want to delete, and so on. All of these would be annoying or painful to have to recreate from scratch, and all of these addons offer a way to back up ('export') and restore ('import') their settings. I've done that before (although not for all of my addons), but up until now I've only been doing it very sporadically, as in once every few years (when my settings for some extensions change much more often).
That's why I say back up your Firefox addon settings every so often. You never know when you may need to remove and then re-install an addon, and you can even do it accidentally (for reasons out of the scope of this entry, I once accidentally removed uBlock Origin). It'll also make it much less painful if you ever have to completely redo your Firefox profile. And you can also use your backups to set up a new instance of Firefox elsewhere, for example on a different machine. Unfortunately you'll have to do this by hand and addons don't have a consistent process for how to do it, which for most people (me included) does get in the way of doing it regularly.
(My initial fediverse post for backups was just about uBlock Origin and uMatrix, which are the addons where things change the most frequently, but the more I thought about it the more I realized it also applied to most of my other ones too, especially Stylus.)
PS: Since I did the Internet searches, see this answer, this answer, and this question and answer for information on where Firefox stores an addon's data (including your settings). The short version of all of those answers is that you probably don't want to try doing this unless you're really desperate to get the data out, although it's technically possible.