I remember being in the GrapheneOS room and hearing them directly recommend using Windows 10 over Linux, as it was more secure. They are known to prioritize security over privacy.
On paper, I'm sure Windows does have stronger userspace and kernel-space protections against intrusion and such, though I most certainly wouldn't use it.
They largely ignore any threat that could come from US agencies, and are very presumptuous about some of their convictions (e.g. that open source is irrelevant for security).
There is a balance to be made, given that there often isn't any ideal option, but they often get that balance assessment wrong, in my opinion.
I appreciate exposing the security weaknesses of other products, but they end up adding threats that they don't have with some of their drastic views.