Paragon levels add more stats to your character. Once people hit 800 , paragons only go into base stats ( Vit/dex/int/str/. Why does that make a difference ? It's end game stuff. 5 extra base stats might not seem like much but spread out on 2000 paragons it directly affects the leaderboards for Greater Rifts. That's why a group of 4 ppl broke the GR 100 this season.