I regularly sit at anywhere from a thousand to several thousand tabs on my desktop browser. I have a tab-counter extension.

I use tree-style tabs. I use this to organize thoughts into groups, or families, hierarchically, with varying levels and numbers of tabs, depending on topic and my interest.

Most tabs are unloaded. I do close and reopen my browser regularly, and restart my pc. I just have the browser remember the tabs in it.

I do occasionally revisit and complete families of tabs. Sometimes I'll queue up loads of things to read on a subject, so that nothing ever has to load or reload.

Tabs are like a working space to me, kind of like working memory in your brain.

Sometimes I'll load in several searches at once.

I have ADHD.

I am also a very passionate and try to be a very thorough person.

I generally do things top-down when researching, but also casually search.

I have waves of purging, myself, but also will randomly close tabs or trees if they are complete or exhausted.

Like once a year or so, the browser has a stroke and decides to flush everything away and I'm sad for a couple weeks.

I have lost amazing things and nearly exhaustive subjects, that alone have been hundreds of tabs.

An example of which was a (near) 100% collection of a web archive that had a complete list and archive of a lost website and organization that personally means a lot to me. I had separated its history into eras, and had found and organized nearly all of a thing that had ever been made by the organization. It's extremely nitpicky and claims almost no storage in my mind or pc. Think of it like data hoarding or zombifying something I deem important and culturally significant. Nearly impossible to do automatedly, and I wouldn't want nor trust a bot to do it, so I did it myself, by hand, in line with a hobby.