Yeah, I think topics should be separated from communities in future Reddit-like websites. I mean it's an indisputable fact that some article is about trains, and what's arguable is whether it needs to be discussed in that particular community.
In my mind it looks something like this:
1) user posts a link (and upvotes some initial topics)
2) other users vote on those topics, also can propose some additional ones
3) topic mods can superdownvote/remove some topics (in case of trolling etc.)
4) community mods select posts for their communities from available posts, possibly automatically (based on upvoted topics)
This is how it works now, and I'm thinking about alternative ways. Communities do also exist in my model, and you can do the same thing. But you don't need to be a hardcore reddit user which has esoteric knowledge like "these articles are allowed in /r/trains1, and these are better to be posted to /r/trains5".
I'm watching Bluesky with interest, because I think it claims to offer that; you would in principle create a ‘feed’ matching (tagged-#Trains AND (approved-by-Trains1 OR approved-by-Trains5) AND NOT rejected-by-CrapFilter23).
The interface is horribly twitter-like but does at least have threading (and unlike !&*#&$ Mastodon, respects `:preferred-color-scheme`), and it's not clear that it couldn't have an alternative old.reddit-like interface.
In my mind it looks something like this:
1) user posts a link (and upvotes some initial topics)
2) other users vote on those topics, also can propose some additional ones
3) topic mods can superdownvote/remove some topics (in case of trolling etc.)
4) community mods select posts for their communities from available posts, possibly automatically (based on upvoted topics)