I am longtime Firefox faithful. But I keep extension usage down to minimum- multi account container, ad block for YouTube, leechblock, clear url, zotero and fpl tools (fantasy football) right now. Tbh Firefox rarely bothers me nowadays with resource usage. I am confident I haven't had to restart Firefox since last November.
My work laptop is a Lenovo P52 with 32GB of ram and win10. Home laptop is a Lenovo legion with 16GB of ram and win11. I had so many issues with performance in the past that I just trained myself to never keep resource-hogging stuff running in background that I am not actively using.
I regularly have zoom and Firefox running while playing MMO games on home laptop. Firefox, SQL server etc. running in background while running multi-core data analysis on work laptop. I never had issues with Firefox, and if there's a memory crash I usually know what caused it. But it is down to hardcore discipline using the machines, and I understand it is not usual patterns for others.
Using Pale Moon with 110 extensions (the original powerful XUL kind, not the lame Web Extensions that modern Firefox copied from Chrome), memory usage rarely crosses a gigabyte on a 12 GB Linux laptop from 2015 with 11 tabs open; currently at 800 MB.
Meanwhile, Floorp - a rebuild of contemporary Firefox - with 9 extensions and 4 open tabs - takes more than double that.
The thing is, I was using the same exact software, doing the same exact tasks on windows 7 with 16gb of ram and I rarely had issues.
Not to mention windows 10 has completely borked my network stack. I can’t get a single WiFi card to work.