*How* we left feeds directly into that - the collapse of the Afghani government was well under way and the Taliban were in fact driving on Kabul during the evacuation. It was very...South Vietnam-like.

In the specifics? Sure. But there's no plausible scenario where under a Trump Administration, the prior Afghani government would have resisted falling to the Taliban upon our withdrawal. Their armed forces and domestic security forces were utterly incapable of preventing that takeover. The same outcome would have occurred under Trump - it was baked into our decision to withdraw from the country, and Trump had already made that call.

Do we still have troops in Iraq?
What about Syria?

And in Cuba. But we have absolutely no control over the government in those countries. Merely retaining a military base or troop presence isn't enough to let us prevent domestic forces that we dislike from seizing control of the government.

Once Trump decided we were going to withdraw from Afghanistan, the country was going to fall to the Taliban. The assumption that Trump (and later Biden) made was that the Afghani security forces were capable of resisting the Taliban. That proved to be completely false. Since Trump would not have had any reason to revisit that assumption - nor any willingness to spend years and untold resources trying to change the readiness of the Afghan forces even if he knew it was wrong - there was no way that things would have turned out any differently.