It boggles my mind that, not only do people do this, but it's common. I've seen managers at work with hundreds of tabs open, with an uncanny ability to know exactly where the thing they need is.
I've been using tabbed browsers for 20-something years and I never really have more than 1, 2 at a time. If I need to call something back, I either bookmark it or I open up the history and search for it.
Different strokes for different strokes. There is nothing wrong with how you use tabs, and nothing wrong with how others do. It is just different. The important part is that whoever can find things later that the saved for later, if the system works for you it is good. You don't even need to understand, since it is your/their personal system.
Now sometimes a different system is better. So there is nothing wrong with understanding - you might learn something that helps you. However it is optional if you are not aware of defects in what you are doing (but if you are aware of them...). Also technology marches on and so something better might come out in the future: keep an option mind.
The important part is to be slow to criticizing people who are different.
Same, if I have half a dozen tabs open that's a lot and I start to lose track of which one is which. Cannot imagine how I'd manage hundreds or thousands of tabs.
It sounds like when you, say, compare a bunch of different products, you have an uncanny ability to know exactly where in your tab history those products are? I really have to open them in a bunch of tabs as I go, and then I can quickly switch between them when I'm at the point of making a choice.
I'm also baffled by the number of (also smart) colleagues
with completely cluttered, unreadable tab bars
using computers with severly degradated performance.
.
When a simple, clean bookmark hierarchy (under the tab bar)
plus a working set of open tabs for the task at hand
is so much more productive...
I think it comes down to differences in how our minds work. Some require neatly organized desks while others thrive on what to others looks like a chaotic, scattered mess of unrelated documents. It's kind of hierarchal vs. spatial, and it's also one of the key differing principles between Windows-style and Mac-style desktop environments.
I have 10 windows open and 8 of them have about 20-30 tabs (two of them have less than 10 each), I don't think my hoarding is thriving. It's more of a scatterbrain saying "Oh I'll get back to that idea", and taking days or weeks to get back to it.
In Vivaldi, vertical tabs mean each tab takes about 40 vertical pixels of height, and about 250 pixels width, so I can skim through the titles of each tab...
I have 546 tabs in Firefox (on macOS) at the moment. I've never noticed any degraded performance. On my phone (iPhone) it's 490+ but that's because 500 is the max. I don't think it keeps them truly loaded until you go back to them.
Now my bookmark list is crazy. I have started using 'open all' and then reviewing items in each folder to see if they are worth keeping. 99% of the time. no. Many times they are from years ago and the site doesnt even exist anymore. I have some items in my folders that go back to 1992. I have a bad habit of 'oh that is mildly interesting ctrl-d time'. Usually a few weeks later 'what was I thinking'.
My tabs however are wildly focused on what I am doing right now. Once that task is done. I close them out. Think my max is 20 tabs. But usually I really only need about 5. The rest I close out. I probably can find it again with search. That is how I found it the first time...
That also reminds me, time to delete more folders.
Ditto on the working set.
For the 'crazy' bookmark lists:
I now have 220 bookmarks, max 4 levels deep, counting the bookmark bar as level 1.
And that's work and private combined.
Before I add a tab to the bookmarks, I ask myself:
Am I likely to need this again?
If the answer is not a full yes, I just close the tab.
It can also be found again quickly enough with a simple google search
or the browsing history.
My tab hoarding has evolved a bit. I use separate windows that are mostly subject-based now. I might have an Amazon window that sticks around for several days that will explode with tabs before I decide to put in an order. If I get on a Factorio kick I end up with a window with dozens of blueprints and forum posts that will stay for a few months (until I get bored/overwhelmed with the game again...it's a cycle, that one...). I usually have a "main window" with stuff like email and nextdns allow list (stuff that I tend to fiddle with often) and a discord/reddit window. The wikipedia window comes and goes but sometimes gets several dozen tabs and might last a few days.
Always vertical tabs since forever. I feel like if I bookmark something I probably just missclicked at some point, it's just never been in my flow, even before tabs restoring on launch and automatic tab unloading.
I've been using tabbed browsers for 20-something years and I never really have more than 1, 2 at a time. If I need to call something back, I either bookmark it or I open up the history and search for it.