I would say 90% tabs are unimportant, but I am afraid to nuke the session from orbit because there are some hard to find links / important ones in there.
Are they easy to find in the list of 4400 tabs?
Thus according to this strategy I would just nuke my session and start from a blank sheet as I won't be missing it. For the same reason I donated and sold tons of stuff over the year before each move because I realised there is no point owning something you use only every 10 full moons or can't even remember it is hidden somewhere in a storage room. You can borrow/rent that to someone.
Besides, you should still have the links in your history.
Each project gets a new note in Obsidian or OneNote or whatever note taking tool you are using. Each day gets a new #H1 heading with the day. Any relevant URLs get added to the note.
At the end of the day, review your notes and clean them up to be concise. Explain to your future self what you did and why those links are important.
Then close your browser tabs, they are saved in the notes.
If you need the content from the website itself (maybe you are concerned about the site disappearing), use something like Pocket or copy code snippets, text, etc directly into the note. Screenshots help too.
Personally, I have stopped trying to understand why people do it. I’m just not wired that way. I am fairly sure my way of organising and sorting through information would be similarly bemusing to someone from the other side. If you are in product, it’s just a good reminder that you are not representative of your users.
It may be working for you.
People who easily accumulate 1000s of tabs, though, would now have 1000 page notebook and 1000 tabs. Don't ask me how I know.
I suspect the major browser vendors are not incentivized to create a solution for this problem. In the case of Microsoft and Google, they'd prefer you avoided bookmarks and asked their search engine so that they can serve you ads. Apple has never prioritized cross platform conveniences, so that leaves out Safari. Firefox is better about this, but only with other instances of Firefox.