I use tabs as temporary bookmarks. It's still a lot, sure, but it comes at no cost.

The browser with the highest tab count is the one I use for HN. 21708 right now. The oldest tab is about 3 years old, which reflects the last time I bothered to clean them up.

It's also a measurement of how many HN articles I read. About 20 per day, I guess. I don't usually close HN tabs when I'm "done" with them. I can't defend that practice, really. In the short-term, I might reload to see more comments. In the longer-term, there are some that I will want to revisit. Actually, for particularly relevant/useful comments, I reopen them in new child tabs, so that they're easy to find and see responses to. This inflates my overall count.

Anyway, older tabs scroll off my sidebar viewport and I can mostly forget about them, but I don't want to simply close them all. Obviously the vast majority are closeable, but again, keeping them around has zero cost.

Someday I'll winnow them and sweep the remainder into (real) bookmarks. Or maybe I won't -- it makes little difference, as it turns out.

There's a subset of people that likes collecting tabs and thinks it's some impressive measure and I've encountered them more and more recently, I guess as some attempt to brag that their computer can handle something? It's like saying you have 30000 pieces of junk mail in your living room. It's just sloppy.

30000 tabs is about 10x as many pages as there are in the entire Harry Potter series. Nobody remembers all pages in those series. Nobody remembers why they have 3000 tabs, much less 30000.