I don't understand the obsession about Biden's age. He's done great work and had one of most productive terms in the last century. Look at all the bills he's gotten passed, the judges appointed! He lost some fights but those fights were probably not winnable if some other Democrat were in his place. Who gives a shit if he's old if he's still able to do the job?
Meanwhile it's a statistical fact that incumbents have an easier time getting elected than new people. It would be certifiably insane for the Democrats to put a new person up instead of an incumbent, it would be tantamount to throwing the election away. When the stakes are this high, why would they ever do that?
They're not saying the withdrawal was quick, they're saying the takeover after the withdrawal was quick. Which it was, Pentagon officials said it was faster than all their estimates.
https://www.cnbc.com/amp/2021/08/16/how-afghanistan-fell-to-the-taliban-so-quickly.html