This hasn’t been my experience at all in the slightest.
Been programming since I was in elementary school, and current Copilot, OpenAI and even Gemini models generate code at a very very junior level. It might solve a practical problem, but it can’t write a decent abstraction to save its life unless you repeatedly prompt it to. It also massively struggles to retain coherence when it has more moving parts; if you have different things being mutated, it often just forgets it and will write code that crashes/panics/generates UB/etc.
When you are lucky and you get something that vaguely works, the test cases it writes are of negative value. Test cases are either useless cases that don’t cover edge cases, are incorrect entirely and fail, or worse yet — look correct and pass, but are semantically wrong. LLM models have been absolutely hilariously bad at this, where it will generate passing cases for the code as written, but not for the semantics of the code being written. Writing it by hand would catch it quickly, but a junior dev using these tools can easily miss this.
Then there is Rust; most models don’t do rust well. In isolation they are kind of okay, but overall it frequently generates borrowing issues that fail to compile.