That's why I'm pretty optimistic about the AT protocol: you get the advantages of app-driven innovation (need a new feature? just define a lexicon for it) without requiring data reliant on that feature to live in that application's silo; the records all exist in each users' PDS, under each users' own control, no matter which applications use those records. And of course, if those features prove to be good ideas, other applications can adopt those lexicons and they're immediately interoperable.