Well, all your alternative major browser engines are from Google's Chrome. If your concern is degree of tight association with Google, you probably don't have preferable realistic alternatives.

I'd also add that I'm not particularly worried about Firefox. Maybe one day, but as things stand, I'm fine with 'em.

problem is that there really isn’t much alternative currently:

• you can switch to a Firefox fork like LibreWolf or Mullvad
  • or Tor Browser and live with no cookies, no saved logins, etc.
• you can go through trying to maintain Firefox + arkenfox if you want fine grain control
• you can switch to any of the Chromium forks which puts you back at the starting point
  • and then you have to deal with lack of ad-blocking once Manifest V3 goes mainstream
• there’s a huge pile of smaller, independent, or specialty browsers out there
  • but ad-blocking is hit-or-miss and plugin support is often non-existent
• hold out hope for one of the up-and-comers
  • Servo – just the engine at this point, who knows how long until a full browser is ready
  • Ladybird – if you want to be associated with the “problematic” opinions of the developers …

Librewolf is a good fork and Ladybird might become a thing eventually.