The only frequent flyer program worth it’s salt for the average person IMO is Southwest. Since I fly them almost exclusively, I have their Rewards CC for my monthly expenditures. I get double points or something like that for booking my flights on it then I just expense the flight. I can cash the points in for all kinds of stuff if I want. They also have a ton of categories where you can earn bonus points back. If you want to use your points for flights, they can go pretty far if you book in advance. I flew the fiancée to Chicago last month for 12k points. That’s about 3 cross country flights worth of points which I’ll clean up on by the middle of April. It’s not the best card for most people but works really well for me.
As for cash back rewards there are any number of better options though. Our company owners switched over to an Amex Business program of some sort in the middle of last year. They are still using up points, cash and whatnot from whatever the old business program we were on with our old BB&T cards.