Right but you're talking about an abstraction and the abstraction will leak at least somewhat.

A modern language can present you with what appears to be a doubly linked list, but is actually just a veneer over a data structure that actually performs well on the hardware. But of course you'll write programs that treat it like a linked list, so they'll have markedly worse performance than was necessary and worse, you may try to "improve" this based on your erroneous mental model and make things even worse.

I think that's where you got to with ORM too. The object store is an abstraction, but it somewhat leaks the fact that there's actually a relational database underneath. If you really just wanted an object store, this will be slower and clunkier than it should be, and if you really wanted a relational database you shouldn't have ORM.

So this is the problem, exposing the right abstractions. Making easy things easy, and yet not making difficult things impossible. Trying to discourage the programmer from using a huge fixed size array and a counter when what they actually needed was a growable vector, but not preventing them from using that fixed size array with a counter if that genuinely is the correct way to solve their problem...