We flew Delta because they were not selling the middle seats and also upgraded to Comfort+ for some extra space between the others. Overall, the flights were great an the airports were completely dead. There were very few small children (aside from our 2), but the age range aside from that was all over the place. That said, I was not pleased that we had to travel. We also didn't get sick, so that's a plus.
Much fewer families than usual for that leg at end of summer. Seemed like few seniors, as I recall, but I didn’t really think about it and am not sure if it was fewer than usual.
Both flights were “full” - in the no strangers occupying middle seats sense. One surprise - on the return they changed our seats at the gate to squeeze our family into 4 seats (taking a middle with 3 of us across one side of the plane), to open up another seat for someone else (5 in the row of 6, 1 empty seat separating the stranger). We expected to have a full row with 6 seats, so the surprise was a bit annoying, but there was clearly no point in arguing so we rolled with it.
I flew Southwest. There were not any families on either flight for "Family Boarding" between the A and B group. Mostly adults/couples. There were about 70 people on my way to Ft. Myers and about 45 people on the way back.
The woman across the aisle from me wasn't interested in wearing her mask over her nose. Flight attendants told her multiple times throughout the flight to cover her nose. She'd shift the mask up over her nose while they were standing near her and then shift it back down when they walked away. Really annoying.
We noticed the typical passenger load had shifted from families with young kids to individuals and couples.
It definitely trended younger with most in their 20s and 30s.
And was shocked at the number of older people on my flight. It may well have been a result of the particular flight (Chicago to Ft. Myers), but crowds in the airport didn't strike me as being younger than normal. My main takeaway regarding the make-up of the passengers was that there seemed to be very little business travel. Lots of couples, families, etc.