Sltldr: “They’re just throwing away money, planting trees in the desert for them to die.”
The Great Green Wall is a top down, big government intervention that has little to no local buy-in and isn’t sustainable without continued big government funding.
Not surprisingly, the funding has mostly dried up, and so has the land.
Alternative summary feels intentionally misleading, when it’s clear your intention was not to summarise but start a discussion on a related tangent (which is appreciated).