Then there are only a few relays for a topic, which means centralization and censorship.
#hashtags need to get easier/smarter.
Remember when everything used to have folder structure, then instead it became tags? It has tradeoffs, but it was like moving from two dimensions into three.
The closest reddit has is cross-posting.
I think for now all we can do as users of the platform is to "help" each other by adding hashtags when OP forgets...