I went from the military, to a major airline, furloughed, flow down to regional, then to Fractional. I declined recall to the major 2 years after starting fractional flying.
Biggest reasons I stayed:

-no commuting. That was a huge reason. During my airline career I commuted from CLT to: PIT, DCA, BWI, PHL, BOS. I'd had it with commuting. Since CLT was senior I knew I'd be doing it again for quite some time.

-variety of flying. I think someone already mentioned this. It was rare for me to fly a 5-7 day trip and NOT see a new airport, even after 12 years.

-I liked just having 2 pilots and a jet. Sometimes we kept the same jet for the entire tour. Cleaning and stocking wasn't something I looked forward to but it wasn't that bad.

-I upgraded in 2.5 years at NetJets. I think both them and Flex are well under 2 years now. I spent 10 years as a Captain at NetJets and could still be there at age 66 if not for medical issues. Had I gone back to USAir/AA I might have held Captain in CLT for a year or two prior to age 65.

There's other minor stuff like a gazillion hotel points, airline miles, and fuel rewards. Flying out of CLT most of the time I was Gold status and about 1/3 to 1/2 of the time I got upgraded to 1st class.

The main difference is schedule flexibility. You don't have that much at a Fractional, even when senior. And of course the longer tours. Some like the predictability of the 7/7 and 8/6, some can't stand tours that long.