I am amazed that a rag tag and bobtail army with battered white Toyota pick ups and some guns mounted over the cab defeated two super powers. Now they have 85 million dollars of sophisticated arms left behind for free, some which were deactivated and possibly repaired. Afghanistan is a very complex country of regions controlled by war lords often fighting each other, different cultures and interests. Farming; I hardly think so despite foreign money, the profit is drugs. Corrupt western backed Afghan government did nothing for the country. Mind, there is great profit for perpetual war, Russia and China next?
Prior to the US arming the gurellas with modern weapons they were defeating the Russians using WW I and home made rifles.
We tend to forget that the USA armed the mujahideen with modern weapons to fight the Russians and trained them how to use the to the best effect .
The Afghan regulars could only keep them subdued with the support of US air power.
So when the air power was withdrawn the regulars had no chance and they knew it
Had the US trained the locals to fly the helicopters and support aircraft then things would have been totally different but the locals were used basically as cannon fodder.
There their is moral
The Taliban fighters were fighting for a cause they were very happy to die for
The Afghan regulars were mostly there because it was the only paying job they could get
Then there is the question of corruption withing the chain of command and from what I have heard the Afghan regulars were much like the British army up to WW I.
All of the officers were there because of who they were related to and not because they had military skills .
Then finally the people saw little difference on the ground.
Much like Iran under the Shar , once you got 1/2 mile pas the city boundry there was noting. 'No police, no electricity , no water , no sanitation , no jobs , no healthcare, no schools and no protection from the Taliban ( or any other militants ) so basically nothing changed since the the days of the British Imperial rule .
Part of the deal between President Trump & the Taliban was the early closure of the Bagrahm air base so there would be little to stop exactly what we saw happen.