I don't understand how/why older employees will earn higher salaries than younger ones. Don't younger ones often have higher starting salaries than the older on

I don't understand how/why older employees will earn higher salaries than younger ones. Don't younger ones often have higher starting salaries than the older ones, even after adjusting for inflation (because the skills of the younger ones are presumed to be more cutting edge and because the dev shortage continues to grow). So, all other things being equal - number of moves, % increase, inflation - won't the younger ones start and finish at a higher salary than the older ones? Having said all that, I do agree that much of meritocracy is a myth...just not necessarily for the reason(s) stated.