Not sure if I'm the "this guy" you're referencing. Anyway, the U.S. did not leave behind sophisticated equipment to the Afghan gov't. They didn't want it falling into Taliban hands. That policy is one reason Afghans did not fight hard. They don't want/need training. They need some A-10 warthogs, drone systems, etc., etc. The media like to throw about big numbers, like $1 billion, but they don't explain that it isn't for equipment the Taliban can get its hands on, or isn't equipment that gives them power projection.