I think what differentiates efficient use of AI vs bad AI output is not AI skills themselves but comfort in understanding AI output. So domain knowledge and technical knowledge. Everything all these AI gurus preach is like snake oil or old wife's tales. There's no A/B testing done to validate any of the "context engineering" hacks or whatever. It's all based on anecdata.
I agree on the first part. the last part is simply wrong. adding engineering principles around AI have measurable outcomes (at least for software development). look at Agent Control Theory from Mark Pollack.