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...
Dashboards can easily take two or three tabs.
The bug tracker is opened on a tab as well as the ticket page. You have a pull request opened to review it, and you check something in the repository. Pop open a couple of diffs to check where someone messed up in the past.
And in the meantime you have Spotify/YouTube.
A dozen tabs easily.
Factor in task switching, checking CICD pipelines, and of course HackerNews opened somewhere, and you can get multiples of that.