May I ask a question about the dynamics here??

I have been following this thread for a long time but since I cannot participate due to geography, I have not considered how the cards that are advertised are being utilized, which is my question.

People are buying the selected GCs (for example this week it is Apple cards) for the boost in rewards points that one gets. But what do you do with the cards? I can understand that if they are VGCs, then the usual MSing parameters apply, but what about Apple or Happy cards. Are they used organically??

Or is there some secret sauce that I am missing.??