The endgame of online communities is the formation of digital nation-states, complete with their own totally online governments.
Overlay communities will become overlay governments.
These online nations will administer our social programs and kickstart the workforce. Legacy governments will be left to become groundskeepers in meatspace.
With the emergence of crypto, these communities can easily collect their own membership dues and use them to redistribute funds to the community.
Communities will compete and offer radically different perks. Some will fund startups and up-and-comers in their space or even create their own UBI. Others will fund conspiracy theory investigation task forces. Online Utopia will fight with QAnon over citizens.
Estonian E-Citizenship provides a glimpse into the future. If one country on Earth is willing to issue a passport for membership in one of their friendly overlay governments, the whole system becomes viable.
You could realistically exit your nation of residence without needing to physically relocate. Just as states now need to compete to host remote workers, legacy nations will need to compete for the benefits of hosting E-Citizens.
Our institutions are crumbling around us, but our lock-in is high. Instead of replacing what came before, the next step is to build on top.