I'm not sure how you square this with promotions (the main driver of performance reviews). No company who hired me five years ago could have kept me with a constant 3% increase, that is significantly less than I achieved through promotions, the rate would no longer be competitive.
This era of CS was probably unique in the history of STEM of having high salary rewards for changing jobs quickly. This never existed in Medicine, Maths or Engineering really (unless you found your own company or such.)
Also, even without boom times top engineers will still make a lot of money because top positions are still insanely hard to fill. I know of several top companies with L8+ positions that have been sitting vacant for over a year, competition for these candidates is fierce.