I need to get into D&D, because I'm clearly missing a lot of context, but that's an impressive speed even before you take into account that this is a person, not a jet plane.
The context is move speed is one of the few things that stacks geometricaly regardless of source. So you can keep adding more effects that buff speed forever. Also there's multiplicative jumps. Walking is 1x, a jog is 2x, and a run is 4x. BUT some abilities adjust those multipliers rather than the base speed number. And if you convert those numbers from "5 foot tiles per combat round" to "feet per second" by simple math. A tile is 5 feet, and a round is 6 seconds... Normal speeds in the game are reasonable and line up with with a human's move speed. But after some buffs it starts to get crazy. If you apply all possible buffs (bearing in mind this prevents the character from doing anything but being fast), you get this. Which I created by timing the speed of this guy jogging using pixil math and scaling and frames per second, then sped up to match the speeds at each point. The last part "mythic surges" are a thing you can only do if your game is using the mythic system, optional side rules. One of which is "You get a number of points you can spend on things from this list." one of which is "+10 move speed" and you can in theory suddenly dump 20 points for +200 move on them. So... Yeah.
