There are some degradations, just like other "engineering" like software engineering. I am pretty sure most people don't know the ins and outs of everything tha

There are some degradations, just like other "engineering" like software engineering. I am pretty sure most people don't know the ins and outs of everything that makes code run, from compiler to CPU, especially not the CPU's of today, I doubt any one person fully understands them. You just know the abstraction layer you manipulate and learn techniques how you can make it do the things you it want. That is quite similar to prompt writing. You can certainly get better at it by learning the basics of LLM models, as well as finding and applying certain methods that improve the results. You can actually see quite a lot of difference between someone trying out some things, or someone who has spent quite a bit of time trying to make it do non standard things. What you call "engineering" is of course up for debate, but it's not snake oil.