Is this the reason for the crowds?
Partly.
(The rest of this is entirely speculation, sometimes well-informed, but usually not.)
A lot of people had travel planned (or at least, expected) in the first year or two of the pandemic, and most of those trips didn't happen. That money they didn't spend on travel (or commuting, or restaurants, or or or) just sort of accumulated, along with unsued timeshare weeks, unspent frequent flyer miles, and so on. Once the curtain started lifting, there was a lot of money (and timeshare weeks and frequent flyer miles) burning holes in people's pockets. Even then, it took a while to get going full tilt, and my guess is that's only happened in the past six to eight months or so---about the time the aviation mask mandate was lifted.
So, there's a lot of unspent travel dollars, and that's before we even added the dollars that folks would ordinarily have set aside this year for even more travel. Just as with my timeshare weeks, it will probably take folks a while to spend that down. Maybe not all will be spent on travel, but while it is let the good times roll.
There's also the "pandemic rebound" effect, which has nothing to do with unspent money, and everything to do with The Roaring Twenties Part Duex. Ever wonder why the 1920s were a decade of wretched excess? Yes, WWI had just ended, but the late 40s/50s didn't replicate that when WWII ended. Sure, there was lots of money and prosperity and all that, but it didn't come paired with WOOOOOO---that didn't happen until the 60s. The other thing that happened in 1918-1920? The influenza pandemic. About 1/3 of everyone walking the planet infected, and roughly 15M-50M dead (and maybe more) out of about 1.8B people---so on the order of 1-3%. No wonder they all got drunk (in spite of prohibition) and put on tuxedo hats and sequined dresses.
The 1918-20 pandemic was much worse than what we've been through the past three years, and the past three years has been...well, it's been a lot. So we might not suddenly all break out in the Charleston, but folks are ready to let their hair down and
laissez les bons temps rouler. What better way to do that than travel?
[Interlude: Ever wonder why there isn't much entertainment-oriented TV or film about the pandemic? I didn't until my wife brought it up, and then I realized: there basically isn't any. There wasn't much about the influenza pandemic in the Roaring 20s either. People didn't want to relive it. Did. Not. Want.]
Finally, I think there
might be some structural re-thinking in the role of work vs. leisure in our lives. You know the whole "quiet quitting" thing that's been in the news lately? That's just Captial's way of rephrasing-with-judgement what Labor is doing, which is: treating jobs like jobs instead of life callings. When work isn't (or is less of) one's identity, it's a lot easier to start taking that PTO that you used to let expire, and using it to travel. (Seriously. One of my biggest problems when I was in management was staff that let their vacation days expire.) I will not be surprised if we look back on the 2020s and find that folks are taking statistically-significantly more vacations than they did in the 2000s.