I don’t think it’s that fundamental. I mean, Reddit has one shared namespace for subreddit names, but that doesn’t mean that everyone has to use one keyword. Like, you have /r/guns and /r/firearms, stuff like that. Nothing merges those.
And even for /r/patientgamers, there’s overlap. Like, /r/patientgamers probably has a fair bit of overlap with /r/retrogaming (note: !retrogaming and !retrogaming exist) and /r/truegaming.
I do think that making lemmyverse.net’s search feature or something similar that spans multiple instances to help people find communities across many instances more easily would help, and putting support for that in clients. The Threadiverse model of having an instance not index communities until someone on an instance subscribes helps scalability, but if the main way to search for communities only searches communities that an instance knows about, it kind of kills discoverability for users.