Even that is a bit of a strech, at it got released one year after DirectX 8 was made available, and was powered by GeForce 3 class hardware, which naturally came first on PC.
> The GeForce 3 was unveiled during the 2001 Macworld Conference & Expo/Tokyo 2001 in Makuhari Messe and powered realtime demos of Pixar's Junior Lamp and id Software's Doom 3. Apple would later announce launch rights for its new line of computers.
Naturally outside PC, there were other stuff predating programmable graphics, however if we stick to the PC, XBox follows PC, not the other way around, specially since the first one wasn't that great versus PlayStation 2 in market share, even if there were some great games like Halo and Fable.
> The GeForce 3 was unveiled during the 2001 Macworld Conference & Expo/Tokyo 2001 in Makuhari Messe and powered realtime demos of Pixar's Junior Lamp and id Software's Doom 3. Apple would later announce launch rights for its new line of computers.
-- https://en.wikipedia.org/wiki/GeForce_3_series
Naturally outside PC, there were other stuff predating programmable graphics, however if we stick to the PC, XBox follows PC, not the other way around, specially since the first one wasn't that great versus PlayStation 2 in market share, even if there were some great games like Halo and Fable.