Bronze Stars vs. Power Stars

After you get 120 Power Stars there's a whole other quest to go through — and it's way better than the second quest in SMG1. You won't ever get to see it, though, if you stay satisfied with those Bronze Stars.

The stars are exactly the same except being in a different color, and thus the Bronze Star being more dull to have then the Power Star. So you could essentially get the game to play itself with no loss as you said.

Source