Obviously there are some industries where degrees are necessary (law, medicine, presumably academia, although I'm not certain), but outside of those, the limiting factors of how far you can go are independent of where you graduated from. There are some places where the initial hiring process will be mostly filtered by where someone graduated, but in the long term, most people will either hit a point of diminishing returns regardless, or they'll be able to make up the difference.
If you don't it may take you a decade of career time to "prove yourself" and network to the point where you could apply for something similar.
Or you might _never_ get the chance to do that because you are stuck in jobs at "normal" companies where you spend all your time on low impact stuff.
Postgrad degrees still have a lot of value, and open a lot of doors. There are things I learned in my Master's that I probably wouldn'tve been able to get at a deep level working in industry, and for that same reason I want to go for a PhD (even if it might be ill-advised in these times).
I think sales in general may also be one of those fields where education is not that important.
Why would you want to work for those places?
Infrastructure projects are where it's at. Pays well and you're using your technical skills to do some good for the country for a change.