If someone’s take on 9/11 doesn’t go back to at least the early 1980s, it’s probably not worth taking too seriously. It didn’t start on 9/11, that’s just the date millions of people were forced into hearing about the messy and complex conflicts. A witness on ground zero doesn’t become a 9/11 expert.
The 4th season of the podcast Blowback does an excellent job of covering the background, both within and beyond the borders of Pakistan and Afghanistan. I highly recommend it.