In the zero-interest rate economy, it was easy for early to mid-career engineers with average skill to switch to a company that paid them 20%+ more money. I did it myself multiple times.

The current economy and AI have turned the tables. Even today, waiting for three years is pushing it for most folks, but understandable. Career growth is being decimated across the industry, and opportunities simply aren't there anymore like they used to be. You can be dedicated and above average, but you are still stuck in the same industry as everyone else.