I cannot claim to know everything in the universe of workology. But after starting work at the age of 17 and worked almost continuously (barring a few short breaks for full time studies),
for the last 34 years I do have a perspective.
And, I do not hesitate to share it when the need arises. Recently, someone approached me to mentor her about the salaries, levels and what is required to progress.
I narrowed down the answer to the last question to two critical factors – skills and dedication. If you have the skills, and you apply them with dedication, no employer would want to let go of you.
Within reason they will be willing to pay much higher than to someone else you fell short on either of these two counts.
To discuss the levels and remunerations I drew the above rough picture showing 9 levels and commensurate daily remuneration.
Whether you are in the corporate hierarchy, or in corresponding consulting hierarchy, everyone has to find their own level on a totem pole, and this may serve as a rough guideline.