If I were one of Biden's handlers, I would make up whatever excuses not to debate.
I just don't think he'll be able to swing that. In any case, I believe Biden already committed himself to 3 debates.
Pretty sure the Biden handlers will coach Joe to death in order to mitigate the debacle. These debates are going to get huge audiences and if Joe has one of his cringe-worthy moments it might mean a huge hit at the polls. I think Biden will crash and burn during the debates.