If we're doing charts, you should probably superimpose a third: the average compensation of a CEO at a firm with a similar number of MAUs. Baker is probably underpaid, on average, for the size of Firefox's user base.
Does this mean that she's actually undercompensated? No. $3M/year is an obscene amount of money to pay anyone. But her public position is factually correct[1]: she could go somewhere else and make significantly more money, and it's up to the Mozilla board to determine whether that's a bluff or not.