If anyone is wondering where this is coming from, it's a new book by Jake Tapper and a reporter from axios, Alex Thompson, “Original Sin: President Biden’s Decline, Its Cover-Up, and His Disastrous Choice to Run Again,”.
One of the quotes in the book is from senior Democratic lawmakers right after the debate, "who the hell is running the country?" which I assume is where the memes are coming from.
Basically, the crux of the book is they did interviews with about 200 Democratic Insiders and people were seeing signs of Biden's cognitive and physical decline for a couple years but White House staff and Biden family members kept insisting that he was fine.
"The facts certainly point to Biden’s staff having more strategically protected him from public view after the midterms, when he increasingly struggled to handle the basic duties of the presidency. If his mental state was bad, he was in just as rough shape physically — aides were reportedly mulling using a wheelchair to transport him if he won a second term."