One thing that's obvious is that the weakness of the central government led the Americans to take actions that look stupid in retrospect but which were actually decisions based on accounting for that weakness.

Another lazy criticism involves the decision to move troops out before evacuating civilians. This was done to avoid a military rout and at the Pentagon's request, and had Biden instead ramped up the military for a civilian exodus he'd be receiving a different and possibly more damning set of critiques now.

By my count, the Commander-In-Chief started the drawdown months ago and the Pentagon had to reverse and send over 5,000 troops back into Kabul Airport.

US troops in Afghanistan begin packing gear in pullout prep | AP News - April 22, 2021 |

The pullout under U.S. President Joe Biden marks the end of America's longest war after a 20-year military engagement. Currently, some 2,500 U.S. soldiers and about 7,000 allied forces are still in Afghanistan.

The Doha Agreement was made by Trump/Pompeo with Taliban leaders. Joe Biden was left to execute the troop withdrawal. No more, no less ... the time schedule was fixed.

The Obama Administration Strives for Change | East Asian Strategic Review 2010 |

In March 2009 President Obama announced a new comprehensive strategy with respect to Afghanistan and Pakistan, but in response to the subsequent deterioration of the situation in Afghanistan the US administration was forced to rethink this strategy. On December 1 the president announced plans to deploy an additional 30,000 troops, and also proposed to begin withdrawals in July 2011. According to the private-sector website iCasualties.org, 835 US military personnel had died in Afghanistan as of December 31, 2009.

...
According to the International Council on Security and Development, an international think tank, as of August 2009 the Taliban operates freely in roughly 97 percent of Afghanistan's territory. While the Taliban had established permanent control over only 54 percent of the country in 2007, by 2009 this had risen to 80 percent (see Figure 7.1). Security is worst in the south of Afghanistan, particularly the Taliban stronghold of Kandahar province, and neighboring Helmand province, which is the world's leading center of opium production. Terrorist bombings and armed attacks occur frequently in this part of the country. The attack on a UN guesthouse in Kabul on October 28, 2009 signaled that the UN was now targeted by the Taliban. As attacks on the UN by the Taliban had been extremely rare up to that point, this incident caused a major stir both inside and outside the country.

Eight years under Obama administration the gains were training of police and Afghan army and an attempt of nation building by ISAF. Winning time as the Taliban surged and the position of the Kabul government weakened. Blame politicians but don't blame the soldiers doing the fighting. After the Saigon retreat, the American people turned on the men and women coming home.

The Maritime Evacuation of South Vietnam and Cambodia | U.S. Navy |

'Sapere aude'