A thought prompted by seeing instances growing and struggling to have enough resources. Then and now, people in groups trying to communicate something. Hardware became incredibly faster over decades, storage became incredibly more huge, and software bloat kept pace?
They can and do. Every sub has a unique name.
The complaint is that there isn’t a single entity who gets to decide which sub is the authoritative sub for a topic. Which is a feature, not a bug.
Communities will coalesce around certain subs that work, and they will rise up over the alternatives. We’re just in ego-land-grab mode right now.