You might be asking: Why not just play the modern game? Here are the key reasons driving players to private servers today:
"When 2.2 dropped, everyone freaked out about the platformer mode. I logged in, saw 1,000 new icons, and just felt tired. So I fired up my old 1.1 server. I played Polargeist for an hour straight. I died at 98% three times. And for the first time in years, I smiled. It wasn't about unlocking anything. It was just about jumping." Geometry Dash 1.1 Private Server