Just like being in the group "college educated" is not a free ticket to a successful career, being in the group "engineer" is not a free ticket to a successful career.
Is a college educated person in a better position to have a successful career? Of course. Is an engineer in a better position to have a successful career? Of course.
The only difference between an engineer in the wrong discipline and a college graduate with the wrong degree is magnitude.
If only those disciplines would not be shifting. Being in my mid 40s now I have seen shifts to and from mechanical/electrical engineering, physics, biology, chemistry, computer science, business or law degrees and many more.
Actually when I graduated from high school the safest and easiest path to employment that was recommended to us was to study a humanity and become a teacher (teachers here - Central Europe - are much better paid than in the US) or get a business degree and work for a bank or insurance company. Both of these paths seem ridiculously risky now (or at least last time I checked).
As a conclusion I would argue that there is no such thing as a "free ticket to a successful career". Chances are high that at one point or another there will be a surplus of people in everyones profession and almost everyone will experience unemployment or need to shift careers.
Is a college educated person in a better position to have a successful career? Of course. Is an engineer in a better position to have a successful career? Of course.
The only difference between an engineer in the wrong discipline and a college graduate with the wrong degree is magnitude.