You can reopen Firefox in Troubleshooting Mode to test if Firefox's RAM usage improves. If it does, it could be that your theme or extensions are causing RAM usage to spike. After exiting Troubleshooting Mode, try turning off extensions to pin down a specific extension that could be responsible. Note that the more extensions you have, there will be a greater impact on performance, so try to only keep extensions that you actually use.

Going to about:processes will provide a breakdown of RAM usage between your tabs and extensions.

Installing the add-on uBlock Origin can save resources by blocking unhelpful content (ads and tracking).

I would say those are the main things that you can try, although https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-or-cpu-resources is a more comprehensive list.

As a last resort you can save a record of Firefox processes via about:memory and upload it in a new issue on Bugzilla, providing as many details as you can.

Thank you for the help, the resources url you shared truly helped. My issue got fixed following this resource https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-or-cpu-...