Focusing on protocol and decentralisation is putting the cart before the horse. The reason why Twitter, and Reddit in particular work so well is because of sub-communities that form organically. More importantly, discovery was part of the value in using it. It's why every Mastodon community specific to one niche/subject is not very interesting, people are not one single interest, we follow someone we like for one reason, maybe it's they make cool art, then we find out they also make music too, then bam, you discover a new genre of music and the community around it. Decentralisation actively introduces friction into the most rewarding loop of the entire thing. Centralisation isn't the problem, it's just comorbid with shitty governance.