Since it has been obvious for at least a decade that conditions in Afghanistan were never going to improve, the relevant question was whether the benefits of maintaining a significant military presence there (preventing terrorism; protecting women; maintaining geopolitical stability) justified the costs (money; casualties; distraction from more compelling concerns). In my opinion, they did, and I said so. However, reasonable people could disagree on this point. Biden did, and I respect his choice.
With an equilibrium of sorts in place prior to our withdrawal, we pretty well know what would have happened if we had stayed. But what about the people who argue that the concept of withdrawal was sound, but the execution was flawed?
Consider a counterfactual in which the fall of Afghanistan happens in accordance with the predictions of the intelligence community—in other words, the government hangs on for a much longer time. Is the evacuation process smoother and more deliberate?
No. It is human nature to assume that the worst won’t happen until the last minute. The Afghan government would have discouraged any slow exodus, and the citizens would have gone along until it was too late. The scenes of chaos you are seeing today would be substantially similar.
In other words, the critics of the execution of the withdrawal have no case. The only people with a right to complain are those who wanted to stay indefinitely, and they have an obligation to own up to the costs of staying.