My desktop has over 2000 tabs open in Firefox. Memory footprint is slightly over 3 gigs. I usually manage to keep the laptop tab count under 1000. Honestly I think you're the first person I've ever heard praise Chrome(ium) for gracefully handling high tab counts.
I'm not a fan Mitchell Baker or many of the ways Mozilla works these days. But in the pulling crap department, Google and Microsoft have given Mozilla a very low bar to clear.
It costs nothing to keep a tab (you had every intention to revisit later) open, especially when tabs can be auto unloaded to free up memory, either by an addon or the browser itself. Firefox unlike Chrome does not keep squashing more tabs in the tab strip forever, but lets them scroll horizontally out of sight to maintain a readable minimum width for each tab. Over a long enough period of time you can get 2000 open tabs. Modern browsers can handle it.
I'm not a fan Mitchell Baker or many of the ways Mozilla works these days. But in the pulling crap department, Google and Microsoft have given Mozilla a very low bar to clear.