Give the guy a break, he had Parkinson's disease and was still willing to shoot a scene playing golf.
Curb is an incredibly good show that easily stands on its own without celebrity cameos (of which, there have been many). But absolutely, every time Richard Lewis was in a scene it was pure magic. Not only was he an incredible talent and overwhelmingly funny, but you could see and even feel the joy that Larry had when working and joking with his best friend.
Not that Curb was his only success, far from it, but he was just so, so good on that show.