We could show some kind of progress in the topic list, but generally it’s always assumed to be effectively “infinite”, that is, unless the community is tiny it is collectively generating thousands upon thousands of hours worth of topics. More than one person could read in a lifetime, and that’s assuming they didn’t have anything else to do…
I guess we could prioritize the display of topic list progress a bit more, I am not opposed to it or anything, but almost nobody ever asks for it. Seriously! And we practice complaint driven development for the most part.
So people browse and scan, and enter those topics that seem interesting based on the title. If they don’t see anything interesting, they keep scrolling, or try a different category.
The best advice is to try the categories page if you want to slice the topics up a bit more: