Look up 9/11 Truthers movement and "Bush Did It!" to get an idea of the conspiracy theories that emerged right after 9/11. The "Bush Did It!" rallies took place in September 2002, just 1 year after 9/11.
Personally I don't believe in the 9/11 Truthers movement but I wouldn't even know about it if COVID level censorship was adopted back in 2001. Mainstream media was very different back then. Compared to what it has devolved into now.
You're remembering things through rose-colored glasses. Ellen DeGeneres and Laura Dern, Bill Maher and the Dixie Chicks can tell stories of what happened in the 90s and 2000s when you went against the mainstream. In fact, people were cancelled over the silliest things (remember nipplegate?). Government censorship was also alive and well: Under the Bush junior administration, NASA and EPA scientists were not allowed to use the phrase 'global warming'.
No true. 9/11 was a nearly perfect military industrial play and no one could publicly question the US actions post the event. It felt like a lockstep war machine with vengeance at an all time high. You must’ve not lived through it.