Indeed. Getting the info out there is both easy & difficult. To get exposure you need pretty much to use the whale platforms like FB, X(twitter), Reddit etc.
With doing so though. It becomes a competition for visibility. Smaller communities do indeed hold a lot of value However like stores; people are more likely to visit a store in a mall vs going to a solo location. Due to convenance and familiarity.
Things like Discourse Discover can help. However ppl are more creatures of habit that will often stick to what they have become comfortable using. Ie FB alternative like MeWe that is more user friendly and doesn’t share harvest your data and is ad free.
Now if we could get some booming FB groups and Reddit subs & X account promoting a directory of dedicated community spaces using things like Discourse may work
Save the other user benefit using a mega platform. Number of seperate user accounts needed for multiple communities vs joining an all in one.