RSW/ORD two weeks ago, even two CKs were in the back. First was zeroed out at least five days before departure. And this was a flight that was added to the schedule because the daily flight sold out a few weeks in advance. Just a random observation with no proof, but it seems like routes that normally have fewer business travelers like ORD/RSW are starting to return to normal levels faster and are selling out in F many days or even weeks in advance. Even back when I was still a CK, the upgrade on that route was iffy since so many purchased discounted F fares, so I started buying P too or upgrading with miles if there was any upgrade space available (which was not often). A lot of people with two homes are going back and forth, especially now with SWFL pretty much open and IL still pretty much shut down (for no good reason outside of Chicago itself). It seems like leisure travelers are returning to flying faster than business flyers. No proof. Just observation.