I didn’t like where Firefox Quantum was going. So, I stopped updating at v54. So far, no real issues. I have noticed, however, that some websites don't work properly.

Is v54 too old-fashioned? Do you know when is EOL of v 94.0.1?

The old Fx 54.0.1 was made EOL once [https://www.mozilla.org/firefox/55.0/releasenotes/ Fx 55.0 was released back on August 8, 2017.] The old EOL [https://www.mozilla.org/firefox/52.9.0/releasenotes/ Fx 52.9.0esr (released June 26, 20180] would be more secure with security updates compared to the EOL Fx 54.0.1 Fx 94.0.1 was made EOL once [https://www.mozilla.org/firefox/95.0/releasenotes/ Fx 95.0 was released as of December 7, 2021]

Thanks James