For me I use the following:
Temporary containers - This add-on is so amazing and really helps when signing into multiple accounts
UBlock Origin - Add blocker, probably the best available
Dark Reader - Helps to make the web a little more readable and less harmful to the eyes
I have multiple LibreWolf profiles with different uses and therefore different extensions tied to each one of them. For example, I've got one in which I exclusively watch the Youtube content I'm interested; through Invidious of course*. Therefore, extensions like SponsorBlock and Video DownloadHelper are only found on that profile to improve the experience thereof without negatively affecting the other profiles. This is mostly done to protect the profile I use for regular browsing, which is somewhat alluded to by the team behind Arkenfox with "We recommend keeping extensions to a minimum: they have privileged access within your browser, require you to trust the developer, can make you stand out, and weaken site isolation.".
As for the extensions I have on my profile that I use for regular/random browsing; those would only consist of uBlock Origin, Redirector and Skip Redirect. All of which are -to some degree- endorsed by the Arkenfox-team. Though, from time to time, I am guilty of using Dark Reader as well; it's just too good to miss out on at times.