"At successful tech companies, engineering work is valued in proportion to how much money it makes the company" You would think that, but decades of experience have disproved that. Most of management, past first-gen if the company was founded by engineers, is non-technical. Most are (more or less) aware that somewhere technical engineering in software is needed, but they feel that as a threath rather than an asset. I…
What if they're right, and at a certain point engineering is a commodity?
There is a subtlety. Your manager might be able to do your job, with time, but if they haven't spent time understanding the same data you have or the greater context of what you are doing, then they won't be able to come to the same conclusions you do.
Therefore your manager must trust your judgement because they do not have sufficient data to make the judgements you make yourself. This necessary deference is what prevents commoditization. Judgement is also unequal, being informed by experience and quality, further denying commoditization because all engineering decisions are not equal.
The corollary is also clear. If a manager thinks they know better than you and treats you like a commodity, then you are forced into performing a job in a dogmatic rather than analytical or informed way. You may be asked to do things that don't make sense or are even directly counter to the organizations goals because they don't know things you know.