Anyone that was around while Reddit was growing will remember that there were few subreddits to begin with. I think fediverse needs that to happen before expanding.
I don’t know how to fix it. Maybe sub-feddits need to be pruned if they aren’t thriving. Maybe tags in titles would be more helpful until they have enough content to warrant their on category.
They did not. They bought postini. Before then spam was really, really bad on gmail.