Sometimes I dream of building a system for myself with a server somewhere that supports email, activitypub, xmpp, matrix... for internet-side communication protocols - and translates them into something I could interact with via a BBS-style interface (that I could share with friends or use alone).
And not "ActivityPub in this telnet session, email in that" (this is already feasible, with pleroma+addon for AP, email e.g. via citadel), but all of them flowing into a single BBS system (maybe via doors or tosser style interfaces for interactive and asynchronous interfaces, respectively.)
All the asynchronous bits (which includes microblogging and RSS) could even be packaged up Fido-style (FTN is still a thing) for local offline consumption.