Programming/software engineering isn't writing code. It's understanding and designing systems. The code is the way we encode the logic. The runtime/compiler of your language is one system among many engineers have to understand and develop expertise in. When working yourself on problems you learn about the various protocols, interfaces, past design decisions and their trade offs, tooling, and develop your general system thinking. When you delegate to AI you get the resulting artifact but none of the personal growth that comes with developing it.

Think of the recent bun rewrite from zig to rust, around 1M lines of code. If you would have a team do that migration they would very likely have to become close to Rust expert, and develop an intimate knowledge of the codebase, its tradeoffs, have ideas for future improvements, good understanding of the technical debt they accepted, reliability of tests, etc. That's A LOT of expertise you can then apply to other things in your professional life.

Instead they went the AI way. The got the artifact (the migration) in ~1 week. But that's pretty much it? What did they learn from that project, other than the fact the AI can do that work? My guess would be pretty much nothing. And pretty much any other software engineer could have done the same migration. There is zero personal growth here.