A friend of mine, a solid mechanical engineer, ended up going back for an MBA. He said that in 2 years, he learned exactly one surprising thing, one idea that he couldn't have guessed after a little thought. [1] He said that the valuable part was the relationships built up with other people who, over the course of his career, would be placed in a variety of high-flying companies.
That said, I think the relationship network is a huge advantage too. Reminds me of a story about, if memory serves me well, an economic university student, who was bad at learning but good at throwing parties (with lots of vodka). It was in Poland around the fall of the Soviet Union. The guy apparently got very successful because through his parties, he befriended a lot of people people who later graduated and became directors of private and national enterprises.
It was this: https://en.wikipedia.org/wiki/Comparative_advantage