Not them, but with my usual work pattern it is really easy to end up with hundreds to thousands of tabs.
New issue? New i3 workspace with a new ff window and a new tmux session, which each accumulate tabs related to that issue. Workspaces can live for weeks or months and while each instance of ff rarely grows beyond 50 tabs, scale that across 10 workspaces and you've got a lot of tabs.
Yes, the 32gb ram in my work-workstation gets a workout.