> I wonder if this "I want to read this but I'll set it aside for now" model of browsing might be better served with a different UI metaphor...

Sure, you're welcome to design it, I'll even give other methods a try occasionally, but for me every other metaphor has proved worse in some way and I'm perfectly happy working this way, there could be something better, but it isn't bad in a way that I feel needs to get fixed.

We'll, I can think of one obvious problem right off the bat: when you accumulate enough tabs they're no longer discoverable.

Many folks here have offered extensions or workarounds for making finding/searching tabs easier, but to me this is an issue introduced by the UI metaphor, and maybe better solved some other way.

Maybe.

I just observe that tabs seem to be a cumbersome tool for a very legitimate use case, and I gotta think there must be room to innovate.

Discoverability is a bit of a weird metric, if you have very few tabs you don't really need discoverability since you just put the tabs there. So this isn't really strictly worse when you have many tabs.

Have you tried tree-style tabs, for instance?

Sure, I think they take up more real-estate and didn't really improve my workflow.

I'm under the impression that no one (or at least very few people) who have 150+ tabs open at once actually use the tab metaphor, at least by itself. I've seen several people in this thread who discuss a tool for searching tabs. Such a person would seldom click on, or even look at the tabs themselves. They would only interact with tabs through the search system. They have already found a new metaphor. Another common system for dealing with large numbers of tabs is building heirarchies. For example, some people have several browser windows open, each wih several tabs in it. One could limit each window to 15 tabs, and only have 10 browser windows open. Roughly equivalent methods include firefox's tab groups and tab tree. Tab tree in particular stands out as a separate metaphor from tabs. While it maintains the ordered list of favicons & titles used by tabs, it adds a new piece of information to each tab, allowing you to more easily determine the correct tab to switch to.

The better UI metaphor IMO is tree-style tabs. It lets one organize tabs in a similar manner to a folder tree in a file explorer. It's great for research, where you'll need to repeatedly reference many different sources, and maintain a chain of how you found each source.