Earlier quoted context omitted.
In terms of UI stuff, how do you find a tab among a thousand? When the tab page title shrinks and all I see is favicon, I feel lost.
You can of course search open tabs from the address bar. But at least my workflow is to browse through the old tabs and read / close one by one. Also in Firefox the tabs never shrink to just favicon, the tab heads become a scrollable list. Much better than Chrome imo.
I'm quite comfortable with a tab group filled to the point where the tab bar only displays favicons, but hasn't gotten to the point where it lets me scroll yet. That way I can rely on spatial memory to get to the right tab, without necessarily seeing the title!
Of course, searching for the right tab is an option, just like you said. I love the fact that Firefox also activates the correct tab group automatically.