I find this to be intrinsically true in my experience. I was put into senior-level engineering positions very early in my career because I'm a strong problem solver and mentor. I've taken on several positions as a programmer working with a language stack I had little to no experience in without much issue.

Of course there are problems where knowing the code deeply is essential to solve the problem, but those really aren't the majority, if even less than 1% of business problems.

When it comes to what the average developer needs to understand, having a strong grasp on one functional and one procedural language can enable you to solve almost every problem in any language ecosystem, provided the correct resources. If you can do this, you can utilize an LLM for programming assistance well. If you can't, you probably should not heavily rely on one at all yet.