Try Tree Style Tabs.

That's gotten me married to Firefox. The hierarchical vertical tab management makes research and general web browsing far more efficient and productive. It also helps me know which tabs I can close when I'm done.

I did. TBH, it did not do much for me, but I'm pretty sure the problem is me.

I've tried all kinds of tab management things (they're usually a motivation for trying a new browser that supposedly offers a better way) and nothing ever sticks out for me.