Yes, but that was my actual point. If one simple UI design trick is enough to completely flip the choices of users, then consent forms aren't a robust way to collect preferences at all. In fact if you wanted to genuinely and in good faith provide access to granular preferences, giving a more complicated set of choices would be the only way to go about it, and that fatigue is still real even if the design has a legitimate purpose.

What you're saying is true, the only way for the choice to be representative would be to have like a binary yes/no choice because that's simple, but that's not even necessarily what the user wants either. You're going to get a significantly more accurate view of people's real preferences by collecting data, like what Firefox is doing here, and then setting defaults accordingly.