You're missing the point. In games like Quake, with individual 3D viewpoints, things are a lot more subjective. If my computer says my bullet hit you, and your computer says it didn't, we go with what my computer says. because I can clearly see that my crosshairs are centered on your chest, but you probably can't see that my gun is pointed half a degree to your left. Nobody sees anything unexpected, so everyone is happy.
With a 2D game like Towerfall, it's different. Everyone should be seeing exactly the same information, from a Godlike outsider's viewpoint, at all times, so it's painfully obvious when things don't match. If you can clearly see that my arrow missed you by two pixels, you're going to be pretty unhappy when it registers as a hit. If we go the opposite way, then I'm unhappy when I saw my arrow hit you but the game says it didn't.
Good netcode and purposeful game design can hide lag, but they can't fix it. The laws of physics and of networking hardware mean that there is always going to be a detectable ping delay between two sites a few hundred miles apart, no matter how good the connection.