[sidlls]

This is a broad question and really depends on the context and environment.

Outside of major tech hubs the answer usually boils down to "insufficient supply of any quality above poor".

In the major tech hubs it usually boils down to the glut of CS graduates who think they know everything or that they are smarter than everybody else perpetuating the CS hazing ritual that is the modern interview process. The bar is set too high using a bad method of measuring skill: the bad definition of "good" leads to an artificial scarcity of "good" engineers.

Good engineers aren't going to tolerate that crap, and will be able to get positions that outside of the typical hiring process.