Bodybuilding is a sport of comparison. You are as good or as bad as the person next to you.
If you go onstage at 6% body-fat (which is relatively lean) but everyone else is 3 or 4% than you gonna look fat or not as lean next to them.
On the contrary if you go onstage at 8 or 10% of body-fat but everyone else is 12%+ body-fat you gonna appear lean next to the others and most probably you will get complimented how lean you are. It's just how the sport is judged.
Be the leader and set the standard onstage that everyone else should get compared to!