Assuming something like "a REST endpoint which takes a few request parameters, makes a DB query, and returns the response" fits what you're describing, you can absolutely copy/paste a similar endpoint, change the parameters and the database query, and rename a couple variables—all of which takes a matter of moments.
Naturally code that is being copy-pasted wholesale with few changes is ripe to be abstracted away, but patterns are still going to show up no matter what.
It'll even write basic unit tests for your CRUD API while it's at it.
And the less instantly I can write it, the more petty nuances there are to deal with—things like non-trivial validation, a new database query function, a header that I need to access—the more ways an LLM will get it subtly wrong.
If I treat it as more than a fancy autocomplete, I have to spend all my time cleaning up after it. And if I do treat it as fancy autocomplete, it doesn't save that much time over judicious copy/pasting.