I understand the existential dread of closing a useful-or-interesting-but-unread tab. But isn't this what bookmarks were created to solve?
The other use case for bookmarks is creating a new tab and navigating to some website like a blank google doc, twitter, hacker news, etc. This is better handled by history. The most frequently used sites can show up on the new tab screen and show up in the results when you start typing in the URL bar.
I don't see any advantage to regular bookmarks for 99% of use cases. They seem to be a feature that exists due to limitations of hardware and browsers from the early days of the web. It's similar to YouTube. In the old days you had to subscribe to channels. Now YouTube is advanced enough to not require you to subscribe to anyone for it to give you content that you want.
It seems like for people with 50+ tabs, rate_of_addition > rate_of_closure.
Saving state is a fair a point, but I can't think of many read pages where that's important to me + I'd trust it to a browser.
But just to say it: I also freak out when I see someone with so many tabs open that it's like a little Joy Division cover on the top of their browser.