Pretty much every company I’ve been in or know of values a vertical trajectory instead of a horizontal one for its employees i.e becoming a manager nearly always means a faster salary progression than becoming an expert in one or multiple fields.
Why is expertise valued less?
A good plan with average people can still succeed. You’ve built a mediocre house. It has some value.
A bad plan with the best people will fail. You’ve built the wrong house. It’s worthless.
That’s the thing with management, they have impact beyond themselves.