> Rinse and repeat six months later. I’m aware this is an organizational problem, but from what I’ve seen, it’s endemic.

Easy enough: almost no one writes SQL queries by hand these days, not for querying the database nor for doing schema upgrades. It's all done by tools - Doctrine in the PHP world for example. And pretty much no one but actual CS graduates knows anything deeper about databases.

Result is, devs are happy enough if they found something that works, and don't want to risk being the one who broke prod because they applied some schema change suggested by their DBA who doesn't know some random thing about the application.