I went down this path. Yes, Windows includes an inbox USB audio class driver, but it lacks support for implicit feedback. The MOTU interface does not have a feedback endpoint, and relies on implicit feedback, so the inbox driver doesn't work. I think the inbox driver does work for Focusrite's interfaces - I guess they include the feedback endpoint, and both Linux and macOS support implicit feedback so MOTU's devices work there. Apple actually recommend implicit feedback only [0].
Thanks for the information! My Motu (M2) does live on a linux machine and it's been relatively painless, worked on MacOs as well, but required a driver download on Windows. I never dug into why. Audio interfaces tend to be finicky things on their own, I also have an Arturia Audio Fuse Studio that needs to be "rebooted" from time to time, no matter what OS its connected to.
[0] - https://developer.apple.com/library/archive/technotes/tn2274...