The problem with postgres's JSON support is it leads to last write win race conditions compared to actual document stores. Once they can support operations like incrementing a number while someone else updates another field, without locking the row, then maybe.

I don't think you'll see a paradigm shift. You'll just see people using other documents stores less.

We’re already in a new paradigm, one in which web devs are abandoning referential integrity guarantees in favor of not having to think about data modeling.

I’d say they’re then surprised when their DB calls are slow (nothing to do with referential integrity, just the TOAST/DETOAST overhead), but since they also haven’t experienced how fast a DB with local disks and good data locality can be, they have no idea.

Can you elaborate on what's TOAST/DETOAST?

The Oversized-Attribute Storage Technique. https://www.postgresql.org/docs/17/storage-toast.html