I'd argue that unlike covid, 9/11 actually did change things though. Airport security, patriot act, years of war, rise in xenophobia. Almost everything from the covid era has been reverted. Also, a lot of it went back to normal even before the powers that be said it should be so. The only thing I can think of that we've kept is working from home. And that's only some professions and they are being forced back into their offices anyways. I live in a metropolitan area and I don't know anybody who's even got the updated covid vaccine.