I think many people instctively know that something was wrong with the course of events. Others, I think, particularly in my generation, can point to it as the turning point for our lives. I was 13 on 9/11/2001. I grew up, joined the Navy, and watched as our economy dwindled and our rights eroded.
After that point… Large portions of society and culture changed - and I think many look to it as a convenient change for the establishment and an inconvenient change for the rest of us - and 9/11 is where they were able to set it all in motion.
So why wouldn't it be as fake as everything else on the news?
It was much more nuanced, though. As with many things - report something seriously wrong to the proper authorities, and they will sit back and let it happen. If for no other reason than when they fail, they get more money and funding. When they succeed, there is no reason for them.
And, of course, why would the FBI ever impede the CIA?