I got busy and did not respond sooner, but wanted to say that I think you are correct: it’s not merely the listing of Topics, which e.g. an RSS reader could do, but rather their ranking of those topics that was an enormous part of made Reddit so popular.

Although didn’t some forums offer that functionality, even if not all?

So as you say it’s the Threaded content, ranked by users as to priority order, that people want to see.

This ofc is all justification after the fact for us here - for whatever reason, people decided on that name, whether they should have or not, and I guess now the question is would a better name be worth the pain of switching? :-)