Seems like the only organization that was well prepared in anticipation of the US pull out was the Taliban itself ???
The background problem the US had is how much more cost $$$ and lives were they willing to make or in the US's best interests to act as a police force against the Taliban possible activity within the county ?
The will to block out the Taliban was simply not there by many in the Afghan government officials with its created military heads.
That preparedness was not implemented to a level which was needed and the ending result is what happened.
Maybe the years there by the US will not be total loss, perhaps the Taliban has evolved toward not being such a brutal oppressive organization ?
I guess we will find out in the months to come.