correction: 120hz not 144hz.
0: https://www.xbox.com/en-CA/consoles/xbox-series-x?xr=shellna...
That certainly implies many games dont support it.
I'm not really sure what Microsoft is trying to say on your link but the Series X definitely cannot run everything at native 4K.
PC gaming at the high end has always been about spending a lot of money to get the best graphics possible. Consoles always have much better bang for the buck early in a new console generation.
PC components are definitely too expensive right now, for several reasons, including Nvidia's pricing choices
While developers are free to make 4K 120hz their target, few games attempt it, and the ones that do, often make significant graphical compromises or are graphically undemanding to begin with.