Speaking as a technician (associate's degree), every engineer in my country makes easily double what I do. Doctors, lawyers, and engineers are just examples of professions that are paid more for their expertise than their actual work output. I would have to work 60-hour weeks just to get paid what a fresh engineering grad would get.
If you think you're at the top of your pay scale and want to earn more, then you should probably think about further education or look into travel nursing if travel is interesting/a possibility for you. Some kind of specialized knowledge like radiation, imaging, or anesthesiology would probably help.