I think the biggest take away from the speech is:
“I know my decision will be criticized. But I would rather take that criticism than pass this on to a fifth president,” said Biden. “I am the president of the United States, the buck stops with me.”
Four presidents share responsibility for the missteps in Afghanistan that accumulated over two decades.
apnews.com
He could have just cancelled the withdrawal and kept the war going for another 4-8 years and nothing would have changed but it'd be somebody else problem and he wouldn't have to take the flak for it. I think at the end of his presidency there'll be a lot Biden could be critisized on, but I don't think this is one of them.