There was LAMP and then MERN and MEAN etc. and then there was Postgres. Its not quite visible yet, but all this progres by postgres (excuse the pun) on making JSON more deeply integrated with relational principles will surely at some point enable a new paradigm, at least for full stack web frameworks?
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.