Engineering is also the process of development and maintenance over time. While an AI tool might help you build something that functions, that's just the first step.
I am sure that there are people who leverage AI in such a way that the build a thing and also ask it a lot of questions about why it is built in a certain way and seek to internalize that. I'd wager that this is a small minority.
To learn effectively you need to challenge your knowledge regularly, elaborate on that knowledge and regularly practice retrieval.
Building things solely relying on AI is not effective for learning (if that is your goal) because you aren’t challenging your own knowledge/mental model, retrieving prior knowledge or elaborating on your existing knowledge.
1. Talk to people, read docs, skim the code. The first objective is to find out what we want the system to do.
2. Once we've reverse-engineered a sufficiently detailed specification, deeply analyze the code and find out how well (or more often poorly) it actually meets our goals.
3. Do whatever it takes to make the code line up with the specification. As simply as possibly, but no simpler.
This recipe gets you to a place where the codebase is clean, there are fewer lines of code (and therefore fewer bugs, better development velocity, often better runtime performance). It's hard work but there is a ton of value to be gained from understanding the problem from first principles.
EDIT: You may think the engineering culture of your organization doesn't support this kind of work. That may be true, in which case it's incumbent upon you to change the culture. You can attempt this by using the above procedure to find a really nasty bug and kill it loudly and publicly. If this results in a bunch of pushback then your org is beyond repair and you should go work somewhere else.
In contrast, if you're a frontend developer, you don't need to know C++ even though browsers are implemented in it. If you're a C++ developer, you don't need to know assembly (unless you're working on JIT).
I am convinced AI tools for software development will improve to the point that non-devs will be able to build many apps now requiring professional developers[0]. It's just not there yet.
[0] We already had that. I've seen a lot of in-house apps for small businesses built using VBA/Excel/Access in Windows (and HyperCard etc on Mac). They've lost that power with the web, but it's clearly possible.
AI empowers normal people to start building stuff. Of course it won’t be as elegant and it will be bad for learning. However these people would have never learned anything about coding in the first place.
Are we senior dev people a bit like carriage riders that complain about anyone being allowed to drive a car?