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?
If you have those skills, you can apply them to yourself. You can make people value your contributions enough to pay you for them. You can convince people to give you the chance to make larger contributions to the company.
If you can get that kind of experience and are technical enough to identify an emerging idea, you can convince a banker or investor to help you start a business.