Exactly this! I'm also using Tab Center Redux to have tabs on the left side, which seems better UX- and space-wise for me even with just a few tabs open, although in the past I've used Firefox's default UI as well for a long time and it worked fine, unlike Chrome's UI.

This is how my Firefox looks like:

https://dosowisko.net/Screenshot_20171030_203716.png

https://dosowisko.net/Screenshot_20171030_203804.png

Once a while I'm getting to 1000-2000 open tabs and this is a point where the whole UI starts to feel a bit heavy, which is the only reason I clean them up then - navigating is a non-issue.