ORMs like Diesel are definitely very useful. The problem I have with them is that their ORM abstraction often leaks. Fixing these abstraction leaks is a hard problem [1].
Ofc, there has been attempts to reconcile relational DBs with OOP like languages, but they are not very popular. [2]
PgTyped and some similar libs try to solve a simpler problem (typing static queries) and can be used to build more complex solutions when needed.
Writing query result/param type assertions by hand and using tests to guarantee type synchronization between DB and code wasn't maintainable on most projects I have seen.
[1] https://en.wikipedia.org/wiki/Object-relational_impedance_mi...