This is just one sector of travel in the US, but it's one I monitor from time to time due to personal interest. The US National Park system has been experiencing massive spikes, but it's in certain places.
www.nps.gov
The overall visitation numbers in 2020 and 2021 are noticeably down from 2019, but these figures include all properties. When we start focusing on specific national parks, we start seeing a different picture.
Take Yellowstone for example...
www.nps.gov
We were there in 2018 when visitation figures were 4,115,000. We were there again last summer when visitation numbers were 4,860,537. It's also important to note that we saw tons of foreign tour groups (mainly China and Thailand) when we were there in 2018, but 2021 had none of that...at least not to the point that it was noticeable.
Other parks like Arches, Zion, Glacier, Yosemite, Rocky Mountain, and Carlsbad Caverns have seen such massive spikes in attendance that reservation systems had to be implemented. We went to Arches in 2019 when visitation totaled 1,659,702. We drove right in, never waited in lines at the entrance and parking was plentiful. Fast forward to 2021 and they saw 1,806,865 and everything in the park and around Moab, UT was a madhouse.
https://irma.nps.gov/STATS/SSRSReports/Park Specific Reports/Annual Park Recreation Visitation (1904 - Last Calendar Year)?Park=ARCH
Yellowstone last summer didn't feel any more crowded than normal, but others begged to differ. We also went to Glacier, which even with reservations seemed pretty crowded. Everything around Zion was also packed and we saw quite a few angry tourists storm away from the Carlsbad Cavern ticketing counter when they learned they needed to book separate cavern reservations in advance and that everything was sold out. We may be popping into Rocky Mountain this summer, so I have reservations just to be safe.
Hawaii is another one. I saw numerous friends hit the islands this year. Some, who hadn't done a big vacation since summer or holiday break 2019, had 2 years+ of vacation budget saved up and splurged big. While some of this is to be attributed to how the island has been opening up...you can see the big difference in visit numbers between 2021 and 2022.
Is it revenge travel? Is it just US citizens looking for domestic wow-factor travel options that seemed safer (i.e. lots of nature and outdoors vs. being cooped up inside)? Is it just because it "can" be done in a more budget friendly manner (all hinges on how you get there, where you stay, where you dine, and activities you book)? And are other countries/parts of the world seeing similar upticks with their own nature/outdoorsy domestic travel options? I really don't know, but the majority of these stats do point to real surges in travel.