The distinction is that with functions, I can have my automated refactoring tools help me change them safely, I can have my compiler tell me if I get them wrong

The distinction is that with functions, I can have my automated refactoring tools help me change them safely, I can have my compiler tell me if I get them wrong, I can have my automated tests tell me if I get them wrong. By keeping the procedural stuff in the procedural layer and not in the persistence layer, it's easier (for me, anyway, your experience may be different) to keep things encapsulated and make contained changes in contained places.