That’s an interesting idea but creating decentralised social networks seems quite hard. IMHO it’s easier to just use regular web sites running e.g. Wordpress, Discourse or SMF[0].
Decentralized social networks can't or won't do the kinds of orchestration of social interaction that help lubricate getting a social network up to speed. Many of those mechanisms, like bots, are underhanded and exactly what people want to get away from in decentralized networks.
We likely have to live with the fact that social networks are artificial creations, and that they are hostile to many kinds of expression. They probably can and should be better at preventing propaganda manipulation by hostile national adversaries, and at protecting the vulnerable from bullying.
But they're never going to be a force for good. Just a less-damaging vice.