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?
I the pre-Jack Welch America, it was very common to have highly-skilled, very senior technical people making almost as much (and in some cases, more) than the CEO or the company president. This included architects, lawyers, accountants, engineers and any person that was deemed invaluable to the company.
Fuck Jack Welch and fuck MBAs.