Every sane owner of a degree will tell you that the degree is "just" the admission ticket for the corresponding profession.
Well, I consider myself sane and from my experience degrees are very valuable, forcing one to learn to a depth that is rarely achieved by self learning or by on the job experience.
I was working professionally for a few years designing boards and writing firmware with high school education only and then realized how shallow my knowledge was without all that mathematical and theoretical background.
Bottom line, they are not just tickets, they actually made me a much better engineer.
Indeed! And nobody is going to sit down and learn to solve differential equations as a hobby - at least not any engineer I ever met. It's hard work and can only really be achieved after spending quite a bit of time with calculus. Another subject that might be difficult to self-teach.
Fourier, Laplace, Maxwell's Equations? Forget about it! These things are tough!
I'll tell you what is nice about EE school circa '73: We used slide rules and did most of the math in our heads. It's fun to be sitting in a meeting and when a number question comes up, just spout off the answer to a couple of significant digits while everybody else is struggling to find their calculator app. The look of shock when they eventually confirm your answer is priceless. Yes, they'll have more digits but that isn't the point!