The point is not about leaving Afghanistan, the point is how Biden did it. You don't leave 15,000 to 35,000 American citizens behind to be raped, tortured and killed by medieval savages. You also don't give your enemies 83 billion dollars worth of military hardware. And you don't block private parties who are trying to get those American out of there.
Biden is an idiot. The only other president who would have botched this as bad was Obama. No one else in the history of America would have abandoned people and supplies to our enemies.
It doesn't matter that Trump set the deadline, he isn't the president any more and Biden missed that deadline anyway.