Earlier quoted context omitted.
I remember 9/11, saw the second plane hit with my own eyes. Other than airports and flying being more inconvenient nothing fundamental really changed as I saw it. People still traveled, people still flew and so on. Now you just budget an extra hour before a flight.
Geopolitics has seen massive impact since then. For example, the rise of ISIS is a direct descendant of the Iraq war which is a direct consequence of corrupt and criminal decision making by the Bush/Cheney admin in response to 9/11. Debatable if the Arab Spring would have occurred without it, as the Middle East might have been much more stable.
Would Brexit have happened without 9/11?
There's an ancient TIME article I have in my archives highlighting how the Dubya admin ignored Clinton's intelligence team's attempts to hand over info about the threat of a terrorist attack in the US. Would 9/11 have been prevented if Gore had won 2000? God damn hanging chads and rigged elections...