While arkenfox could still be useful I think that Firefox with the recommended settings covers most of the “hardening” for daily use. For the best fingerprint and privacy protection using Mullvad browser is a no brainer.
So the use case of arkenfox is quite unclear to me and his user.js setup and wiki is not as simple as switch some settings for the average user.
Also I didn’t follow the recent developments but wasn’t arkenfox supposed to sunset at some point?