While all of that may be true, the fact that we were so caught off guard by the Taliban is still a problem. I do not know how our intelligence had no awareness of what they were preparing to do and I don't understand why, even without intelligence ahead of time, how we were unprepared for the possibility that they would act.
1. They knew what the Taliban was likely going to do. They did not anticipate that the Afghan army would fold. Maybe they should have anticipated that. I found a statement from the US envoy to Afghanistan delivered to Congress. He said the Afghan army would fight. I don't know -- seems reasonable for the government to rely on our Afghans who have deep knowledge of the government (don't know if he was an Afghani citizen we recruited, or an Afghani-American who we sent over there).
If Biden can be blamed for anything here, it's not anticipating more fully what the Afghani army was going to do.
2. You might remember there were other things going on in the world. You know, there was a disease out there that required a lot of attention from the administration and Congress. And the fact is that the military leaders were being hamstrung by the courts. Courts in Texas and Florida actually enjoined the navy from deploying warships because there were sailors on the ship who didn't want to take the vaccine and the courts decided that military readiness came second to their "religious" anti-vaxx bullshit. It's impossible to estimate just how much time went into this kind of crap. I don't remember exactly when those court decisions came down, but they were a thorn in the military's side for quite some time.
3. You might remember that, after Election Day 2020, Trump's focus turned entirely to stealing the election. IIRC he replaced the head of DOD and DHS with the extreme loyalists, and they went on plotting their schemes. There was also a crazy lady somewhere who was tasked (IIRC) with processing transition team security waivers and she was a Trumper and she wouldn't do it.
So when Biden's team came in, they were facing a huge information deficit and a shocking lack of preparedness. And a May 1 withdrawal date established by treaty.
4. The withdrawal was chaotic but the result was fine in the end. Minimal casualties. We had to leave Afghan allies behind . . . but they were having trouble being processed for admission and the GOP in Congress were throwing fits about "parole" for those people. In any event, it could have gone better but it was not a catastrophe.
5. To the extent that you want to apportion blame for what happened, it would seem to be about 80% Trump. He undermined the Afghan government by excluding them from the treaty making process, which meant that nobody could have faith in it and so there was nothing really for the anti-Taliban people to be loyal to. He insisted on freeing all those Taliban fighters. He committed to an impossible withdrawal date (one he likely had no intention to obey because he doesn't give a fuck about reputation for honesty, which is to say he doesn't understand international relations at all -- but other presidents do care and attempt to live up to treaty promises). He neglected the entire situation for the last three months of his presidency.
And oh, he made zero provisions for vaccine distribution -- again, because he was too busy plotting an insurrection. Biden's people had to start from scratch.