Yes, compound growth with periodic deposit is awesome like that. If you had $270k in your accounts (1.5x of $180k), at even a modest 6% growth rate, $270k grows to $361k alone without new contributions. But if you also keep adding 15% of the $180k gross income each year on top of compounding, $270k grows to $513.5k instead.

Much more difficult if you are already behind (need to increase contribution rate to 28%).

FYI I think the 1x is based on your starting income, not what you have now, so if you re-frame the question with a lower 1x, you might not be too far behind.