No I agree communities have not been explored/developed nearly enough. Competing with Twitter is in some ways harder than competing with Reddit because Twitter is a platform for famous people and thus the "gravity" of who's already using it is stronger. On Reddit it matters less who you are, it's more content focused. People go there for information, not as much for news.
Discussion
Yes, interesting point. As you say, a twitter platform may need personalities, prominent cultural figures / personalities (I would say more content creators rather than influencers, as I think the myth of influencer power is overrated, but that's a different issue lol). Whereas reddit/forum Communities -style would need to attract those groups, migrate some, be known to others which have already been deplatformed or censored. It's a somewhat different beast of adoption lol, and definitely also difficult to pull off, but probably somewhat more imaginable.