From this comment I suppose you never used Librewolf or Arkenfox. The Torbrowser is only a hassle because
it uses “private browsing” always, which completely hinders people from saving anything. This is not needed, as cache, session etc could simply be deleted via the settings.
it uses the Tor network, which is a huge thing. Cloudflare and all that BS block you 90% because of that. Its even worse than with VPN
The real difficulties just come when you use Noscript, or Ublock with hard settings. The hardened browser alone is unproblematic. But if you use Noscript, you dont want to not use it anymore. Sites are so bloated with third party javascript that is simply not needed.
Firefox on Default is not stopping much tracking. It should teach users how to be private. Also work of course, but really. Other browsers will scream out way more data, thats for sure. But Firefox has all these features but nobody knows them.
So, in the end there is no real usecase for Firefox. And people use any other “secure” Browser instead