I think I'm missing something here. You want 100s of pages accessible from a vertical list, but are happy to wait for them to reload when you re-open one... aren't you just looking for a bookmarks list?
Yes, the author says that he doesn't like bookmarks because then they are hidden behind a menu but at this point he's basically recreated a list of bookmarks that is always open.
I also keep plenty of tabs open for things that I'm monitoring or want to get back to but appreciate that browser constraints force me to go through the tab backlog and either deal with the tab now or save it as a bookmark for later.
He doesn't even need the bookmarks, a 'history sorted by access date' would work just fine. IE 11 has the history explorer bar which you can choose 'today' and 'view by order visited today'.
In any case, he could use Sleipnir 6. It's got your hundreds of tabs open market cornered.
Bookmarks (AFAIK) don't store the state of input fields and such on a page, while tabs do (though they probably don't if you're unloading them on-the-fly). So, if you're jumping between, say, multiple pages with multiline text fields (perhaps when authoring forum/blog posts, for example), support for lots of tabs is handy in that case.
Also, bookmarks aren't quite as ephemeral as tabs, so there are different workflow implications.
I've always had 150+ plus tabs open ever since the days of Firefox 3 and I've always run stock browsers + adblock. Both Firefox and Chrome seem to handle it fine, never noticed any performance issues running on fairly standard machines. The key is to max out the RAM of any machine you're on. Nowadays with fast SSDs though, even fast RAM doesn't matter very much.
For tab groups, why not use Firefox's built-in system? The icon next to the "New Tab" button shows you tabs groups and lets you make new ones, drag tabs from one group to another, and name tab groups. Firefox also takes tabs out of memory when they're in a group you're not looking at.
I disable JS. Makes the web much nicer. For the occasional broken site that requires it to render text, hit CTRL-SHIFT-s (using surf) to enable it until that tab (using tabbed) is closed.
I don't recommend it to people, really. I know about the security updates and live with that risk, personally.
My main point was really that the article linked is a silly hacky workaround to a problem that would not exist in the first place if Chrome and Firefox were well written software.
Sometimes I feel like I open way too many tabs, when I really could reopen them anytime, by either using a bookmark or just googling the page (say python documentation). I can't imagine a use case where you needed that many open tabs.
Tab groups is one of the most underrated features in Firefox. I always have dozens of tabs open in various groups, and it mostly doesn't affect the performance.
As a former multiple hundreds of tab users. I did t know I could write a hn article about it. :P
But the way I solved was by not having all 100s+ tabs in 1 window frame. But by dragging out a few tabs into another windows frame. And sorting that way. Combined with multiple 27" 2560*1440 monitors. I never had any issues.
Most the plug-ins are meh or add instability. Never had any slowness or issues with performance or crashes and I'm not doing anything special or different at all. Or at least I don't think I am.
However as of late I've been trying to keep total count under 20. Though it's often quite difficult.
This is how I use Conkeror (Firefox-based Emacs-like browser, for those who aren't familiar with it). Since each frame has its own unique buffer list, it's pretty easy to create new frames (C-x 5 2) and use them to segregate tabs/buffers based on tasks.