The document is comparing salaries of staff engineers, and EM's. In my experience staff engineer positions are even rarer then EM positions.
Where do you work?!? If you are in Western Europe then the blogpost is irrelevant for you. The Western European market is weird.
In these kinds of organizations, software is viewed as a cost-center and as such the only way you as a SWE can protect yourself is to climb up the management chain as soon as possible.