Matrix the protocol & its blockchain-like eventual consistency model is incredibly expensive / wasteful to run since it requires duplicating all data to all servers for the entire history. Matrix uses so much storage & RAM on a machine. Medium-sized servers regularly close their door due to costs—which further pushes users to the de facto centralized hub in Matrix.org (or servers they host for others) which basically has a copy of all metadata on the network (scary since it was originally funded by Israeli Intelligence … so one might assume they still have access to that data). If a system isn’t accessible to a run for groups on a budget, it isn’t radical/revolutionary.

If you don’t care about the centralization or E2EE, IRC/IRCv3 covers all the bases. If you want decentralization with more features, XMPP + OMEMO + MUCs, covers the rest. Neither of these are resource hogs while having over a decade of extra stability. Matrix 2 is just trying throw a rug over the problems of eventual consistency—but under it is a fundamental issue to the protocol.