Absolutely true.

I do believe most engineers experience this maturing when they get access to leverage in the workplace, such as going from being an individual contributor to a leader or mentor.

Try sales for a while, and you will realise that no customer has a neatly defined problem for you to solve. They have real complex problems, which you may be able to shoehorn your general solution into. But even then, there is always an alternative solution for the customer which may be simpler or cheaper, such as just hiring an intern to do the job your software can do.