The next generation of decentralized imageboard development is ongoing. I am studying the plebchan code and thinking about forking it. I am also building brand new server node software. It might be possible to even build a brand new blockchain from scratch (think eth/btc/sol), with decentralized messaging built in as a first class feature of the blockchain. I know dapps exist, but they are not so easy for most people to use and adoption rate is low for consumers.