Because a lot of physics simulations and actor ticking is either reduced, or turned off entirely, when not within close proximity of the player. There are only

Because a lot of physics simulations and actor ticking is either reduced, or turned off entirely, when not within close proximity of the player. There are only so many CPU cycles in 1/60 seconds, so games have to be selective about what they update at full fidelity. (Single precision) float-induced rounding at large offsets would introduce a lot of jitter to these calculations, which looks and feels very janky.