I'm not sure whether I agree with GP, but I think you may be misinterpreting their point. I can have an understanding of CPUs in general without knowing individual instructions, and I do think knowing about things like CPU cache is useful even when writing e.g. Python.

There's generally a pretty quick falloff of how much help knowledge of each layer under you generally provides as you go deeper.

That being said, if you're writing in C, having a pretty good idea of how a cpu generally executes instructions is pretty key to success I'd say.