Trustworthy Computing means that you have the choice to trust Microsoft, as they vend the entire OS - and assuming you actually pay the big bucks[0], you can also be certain the data on the OS isn't being used for advertising purposes.

Windows provides trustworthy computing, but by no means is it required. iOS is the opposite of this where you're forced to trust Apple, which comes with UX inconveniences.

0: https://www.microsoft.com/en-us/microsoft-365/compare-micros...