A friend wanted to develop expertise in a field by getting more degrees in school.
As I wrote in “Programmers work with computers and leaders work with people,” people with functional skills can solve problems in that functional area: carpenters can solve problems with wood, plumbers can solve problems with pipes, and so on.
Leaders can solve problems with people. Expertise is nice, but if you have leadership skills, you can hire experts in fields you need problems solved in.
If you don’t have leadership skills, you may end up the tool of someone who does, helping them achieve their goal. Do you want to be someone else’s tool?
I couldn’t agree with more with your underlying sentiment that functional skills are specific to their domain, and that without cultivating the skill to lead others, one risks commodifying themselves (if I’m understanding your tone properly) as another tool for someone else to achieve their goals.
I always find it interesting, though, when there are people with some technical expertise and leadership skills that are actualizing their goals (Elon Musk, Mark Zuckerberg) as the combination of those two areas seems pretty rare. I think it offers a unique perspective, both from the vantage of being a leader and as a technical worker.