Afghanistan’s informal economy is the prize for the Taliban
nytimes.com
nytimes.com
Informal economy is a reality in every developing/under-developed country, so I doubt the foreign donors aren't aware of it. Being aware of something and talking about it openly are two different things. By definition, the donors can't do anything about the informal economy without having boots on the ground, so why talk about something you have no control over?
The real money comes from the illegal movement of ordinary goods, like fuel and consumer imports. In size and sum, the informal economy dwarfs international aid.