I noted the tab count because it's a weak measurement of memory requirements, which is directly relevant to the topic at hand.
I keep tabs because they're better in most ways than bookmarks. I'd be happy to expound on that opinion, but I suspect you're unreceptive.
FWIW, Firefox with Sidebery can handle more tabs than you or I need. Someday I'll clean them out, maybe, but I don't need to. Thanks to Mozilla, Apple, and Sidebery.
I also set the color of specific tabs (another Sidebery feature) that have some special returnability reason. I don't love the color options, nor the default ordering (would prefer the more traditional color spectrum order (red-blue or inverse) so that I could infer the tag/priority/etc from the color, but I only use a few colors and it's fine.
I don't have a problem with duplicates. If it's a page/app that I return to often, I know that and just jump to it. I'm sure I have some dupes hiding in there though. NBD.