The trouble isn't a lack of the right technologies - I'd argue it's a problem in the go-to-market strategy of those building these products/technologies.
Ideas flow along lines carved out by power/influence. Facebook's early strategy was to start with restricting its usage to people at Harvard University - arguably a highly influential institution - and then expand outwards to other highly influential institutions. Only once the "who's who" from those institutions were already onboard did they let down the walls to allow us plebs in, and we all rushed in head-first.
X's current strategy leverages Musk's visibility and influence (for better or worse).
Get the most prominent influencers onboard with your decentralized social network, and others will follow (dramatically easier said than done, of course). But without a significant contingent of influencers/powerful people, your network's DoA.