The Tegra X1 in the Switch is 384 GFLOPS in docked mode and 152 GFLOPS undocked ... and games have to be able to run in both modes.
500 GFLOPS is a hypothetical top tier performance for the X1, even in the Shield Console is can only hold 500 GFLOP performance for a few minutes before it throttles itself down to 384 GFLOPS.