I left my field of civil engineering for precisely this reason. I remember 5 years out of uni i was on 120k while supervisors were on over 180k with better bonus'. They also had been earning money since they dropped out in year 10 while I earned a handsome Hecs debt instead.
Funnily enough I began small developments and became a supervisor myself. System is broken.
My wife works in the finance sector and earns over twice what I do, not counting share options and bonuses which almost doubled it again. She's very good at what she does but when you look at the amount of study and professional development you need to do to get where I am it is little wonder many don't choose STEM eng or tech.
What makes it worse is there is an entire generation of technical officers, many with trades as well as their technical qualifications, who earn less than those who stayed in trade and didn't do extra study. Many have also gone on to post grad, earning masters degrees in speciality engineering, not MBAs but masters degrees in areas we have a shortage on engineers, and they can't get roles that recognise this.
It has noticeably gotten worse since the demise of the Automotive industry.
Too late for me but if we hope the sustain, let alone build the types of capability the country needs, wages for (proper technical) trade, technical and engineers need to improve, career paths need to improve, and there needs to be a move away from tying pay increases to becoming a manager.
If you've got a technical person with decades of experience, doing critical work very few people can do, including managing complex components of other people jobs, they don't know how to do themselves, while those other people, who have just one job (that they don't know how to do on their own) get paid 50% more, you have a serious problem.
One of the best obsolescence and RAM experts I know, who was also expert in strain gauging and condition monitoring, left and is now making much more money doing electrical testing and tagging. Lots of stories like that. I earnt more sitting on a chair, reading a book while supervising tradies on a defence site than I earn as a defence technical manager now.
The system is broken.