Hazel doesn't close tabs because it's 'like a trip down memory lane.' Mozilla says it has some profile and tab group features coming later this year that might help her organize those memories.
I feel like a power user would have a clean and clear bookmark game, not thousand of tabs... How the hell do you even navigate into this mess? I've just re-organise my bookmarks and folders, imported them in nextcloud, and I feel like I'm the master of the internet.
With Quick Tabs Ported, you don't need to look for where tabs are; just invoke the extension and type any part of its name to find and jump to it. It's been life-changing for me, personally (but yeah, I don't keep anywhere near this number of tabs, still, haha).