How to align browser tabs with its' contexts?

I usually have hundreds of unorganised tabs that I can barely arrange. I just open a different window for a different context (supposedly learning a new thing => new window). But often I don't finish, thus leave them in the midst.

One viable solution I could come up with was the "different profile" thing (e.g. work profile, school profile). Yet opening up another profile for a temporary context doesn't sounds nice (supposedly it might be some tutorial that might take a week). And I don't want to close those tabs/tab groups and leave them like that, so even in that case they occupy some space (mental, or RAM).

Is there a thing which did help you to organise these tabs, so that you could close them and return after a while without actually losing anything?