I've been staying with Firefox not for the performance (today Chrome loads Google sites like YouTube faster), but mainly for Tree Style Tab extension. I couldn't imagine opening more than a dozen of tabs without it.
I can't imagine having more than a dozen tabs open, period. You tab hoarders will never make sense to me...
Firefox/Sideberry is useful for mitigating that. I also have workflows set up for mass-exporting my tabs from Firefox to a text file and reorganizing them in plain-text and re-opening just the tabs I care about[0].
Bookmarking on any browser is cumbersome and leads to disorganization over time. Tree-style tabs helps make that organization at least a little bit easier.
The big change for me has been realizing that all my "tabs" are still there, in the form of my browser history, or if not, via Google search. If I can't find my way back to a website via my history or via searching the web, then I probably also wouldn't be able to find it among 1000 tabs. So why not close the tabs and be free of them?
The only reliable way that I've come across for finding stuff after a long time has passed is saving every sightly interesting webpage to Zotero and using fulltext search afterwards (including webpage body).
I'm curious, do you find the builtin browser history facilities sufficient for your needs, or are you using some third party tool for that?
I mentioned this below, but check to see what your history limits are in Firefox (https://support.mozilla.org/en-US/questions/1039372). It's possible if you do enough browsing that you might have trouble finding older pages because they're not there anymore.
I'm not sure what the best mitigation is for that, I've kind of accepted that history for Firefox is short-term, not long-term. It might be possible to rig up a webextension to save history more permanently, but I suspect it would need to do native messaging I think to do that, and at that point maybe it's better to just do regular copies of the SQLite database.
Relying on Firefox history less also has the kind of minor advantage of allowing you to be more aggressive about cleaning it yourself, which can have a noticeable performance impact in some cases.