My two heaviest used cards are the Amex Plat and Chase SP. Citi TY is a newer card for me (05.17) that currently has a 0% balance transfer I'm paying off (should be PIF by June). I do quite a bit of international travel so the Amex and Chase have come in handy. When looking at my AF I did look at Amex first since it's the highest, but I'm able to maximize/use nearly all it's benefits ($100 Saks, $200 Uber, $200 airline CR, Fine Hotels/Hotel Col, etc) so I feel like I'm getting my money's worth out of it's AF. Plus I'll admit to an emotional attachment to the card since it was my first "big boy" card. 
Chase SP I've only had a few years, but it's come in handy when someplace doesn't accept my Amex. My biggest use of points, mainly MR and UR, are transfering to airline partners for miles.
I agree that going forward I probably won't need both Chase SP and Citi TYP. Once the Citi TYP is paid off I plan to use that more often and see which card I prefer. Next year will most likely see me downgrade one of them to a no AF card.