In Biden's defense at the end, it appears to me that with "I'm right here?" he's confirming with his aides that he's to move next to the table directly in front of the podium to have his meal. He's not demonstrating confusion exactly, but the constant need for direction is a sign of the loss of what is called "executive function", which is sad to see in anyone, let alone a Chief Executive.
Do you want a president who must ask which button to push in a nuclear war?
The rest, showing both the Xi Jinping and Abraham Lincoln remarks, is hard to watch.