The only part that’s tied to your perceived value and leverage are bonuses or new job salaries (and most of the time those are tied to your previous salary). I’m not counting bonuses, and getting over a 20% increase when switching jobs is a startlingly rare event reserved for CEOs and the Guidos of this world.
Also, if you have concrete examples to the opposite, I’d like to hear them. Simply claiming repeatedly that they are merit based does nothing to sway me to your position.
In fact- at Amazon I've heard the opposite of what you're claiming (I've heard this sort of culture referred to as 'up or out')- after a few years you've exhausted your signing incentives (primarily stock options that vest over those few years) and if you stay in the same role for a long time, your total comp will actually decrease
As they say, compound interest is king - companies are just not willing to swallow the fact that the compound interest is in this case working against them. And yes, it’s working against employees as well: after all, no amount of technical experience can fight against 20+ years of compounded interest.
EDIT:
A $60k starting salary, compounded annually at 4% for 20 years, will be $131k. At the age of 50, they’re knocking on the door of $200k. 60 brings them to around $290k. Just by doing their job.
If anyone is to blame for the “unnaturally high” salaries of those over 40, it’s the companies themselves, plus a bit of math.