Exactly but they are not orthogonal as you try to make them to be. That's just trivializing things too much, ignoring all the nuance. You sound like my uncle who has spent a career in the IT but never really touched the programming but he nevertheless has a strong opinion how easy and trivial the programming really is, and how this was not super interesting to him because this is work done by some other unimportant folks. In reality you know, he just cannot admit that he was not committed enough, or shall I say likely not capable enough, to end up in that domain, and instead he ended up writing test specifications or whatnot. A classic example of Dunning-Kruger effect.

There is a nuance in what you say. You say it is "still easy" but it is not. It is not enough to take a course on operating systems and learn C to start contributing to the operating system kernel in impactful way. Apart from other software "courses" that you need to take such as algorithms, advanced data structures, concurrency, lock-free algorithms, probably compilers etc. the one which is really significant and is not purely software domain is the understanding of the hardware. And this is a big one.

You cannot write efficient algorithms if you don't know the intricacies of the hardware, and if you don't know how to make the best out of your compiler. This cannot be taught out of the context as you suggest so in reality all of these skills are actually interwhined and not quite orthogonal to each other.