First, assume many people in power have a little work done to keep them looking vigorous. Second, there's something addicting about it and many people go too far. Assuming though that it isn't the real Biden who had a sloppy surgeon or screwed his own looks doing something demented while recovering, imagine the problem of making someone in the public eye constantly pass as someone else for months or years. Mask mania bought some time to help forget exactly what he looked like. Then you get the double and do some surgery on him, only make it a little sloppy, like the wrinkle behind his left ear and the mismatched earlobe. This could easily be corrected, why wouldn't it be done for the President? To sow confusion and doubt. Finish off with a number of people willing to cruise blogs and prod arguments over whether it is or isn't Biden: some of those seemed strained to me.