Right, the need for college is very context-specific. And PhDs in particular need to come from universities, basically by definition.
But I'm guessing you'd be surprised about the need for college in engineering: I'd guess that somewhere around half of all engineering jobs could be taught perfectly well by apprenticeship rather than university. While I was in college, I had an internship with an industrial automation company; we programmed assembly lines and robots and such, and some of the best engineers in the company didn't have a degree. In terms of real-world "this is how you get it done" sorts of things, I learned at least as much from that company as I did from my classes