I don't know the technical reason for what makes XP's basic VGA driver so slow compared to Vista and later versions but...
...if you think Vista/7 basic VGA is fast, you should see it on Win8 and 10. With a fast CPU, it absolutely flies. I remember setting up Win8.1 and not even realizing that I was using the basic driver until I tried to run a game. I mean, it was running at the monitor's native 2560x1440 and completely smooth! I think that was on a 6700K machine.
Win10 is a bit different. The basic driver seems to run compositor effects at either 30 fps with fairly bad tearing, or 60fps with barely noticeable tearing, like Win 8.1. I'm not sure what determines the speed. I've seen it "choose" 30 fps on really fast systems, but I've also seen it choose 60 fps on slower systems. Seems completely random.
Not that all of this really matters. Just install your dang video driver! 😜