The Taliban closed the opium trade but the big picture is they are still exporting low-value form commodities (raw oil, ore) instead of retaining enough surplus to develop the means to produce high-value form goods (gasoline, electronics, stainless steel medical needles) which is what a left wing government would (did, 1987-1992) do.
If the U.S Government was unsuccessful in supplying and elevating the Gorbachev clique into power and unsuccessful in arming the Mujahideen+ affiliates (which consolidated into the Taliban), the Republic of Afghanistan would probably have fully secularized and industrialized by now.
Any space for right extremism would have been taken up by universal high education, land-reform, cyberneticist economic planning, advanced high-value production and other zero-poverty + full-employment initiatives.