They have no backing from the Western powers. They can't depend on extortion alone.
The Taliban obtains their funds in the form of illegal taxation, extortion and funding from radical Salafis in Saudi Arabia and Qatar. They are also involved in human trafficking and arms smuggling. Opium poppy is not one of the major income sources for them. All of the major poppy growing areas are located in the government controlled parts of Afghanistan.
You can´t mention those Saudi fruitcakes. It´s not politically correct. They are in OUR team. Experts say that what makes them such dear friends of our leaders is first shared mentality and second money, but that doesn´t matter. We stick with our team no matter what. Even if they chop heads off people and jail people for ten years and a thousand lashes for criticizing them. They fund terrorists here and there but that doesn´t matter. What matters is that they´re in our team. Period.