Whereas someone in the industry has been developing their generalist skills and keeping up with current technology.
True. Although if you can complete a phd at Stanford you almost certainly have the ability and drive to get to senior developer level within a year or two in industry. But when it comes down to it most companies don't hire for who you will be or who you can become but for your current skills and abilities.
Which is ok, but don't then turn around and complain about a skills shortage. And don't complain that employees have very little loyalty. And don't complain when you have to pay $150-$300/hr for experienced developers with expertise in your specific stack.
You think you are generalist because you don't even know anything else exist.