if both yamal and raphina won the ballondor in two separate years with a similar performance then both of them fell off and did nothing of note after, are you gonna be saying yamal was a better or more accomplished player than raphina?
by "similar performance" im going to assume you only mean Goals/Assists, so:
Yamal better? Definitely, not even close
more accomplished? No
But thats the point, greatness also takes into consideration your quality as a player. So, by doing impressive shit younger you stablish that you are more talented and naturally better at it than most people, and more gifted players increase in greatness because they are rarer, its all there is to it.