Most people want at least one each of VISA and MC there are places that don't take one or the other, Sams Club doesn't take VISA, but does take MC, Amex is wanted for the prestige and a true oddity of having a place so upscale that it would only take AMEX perhaps places like that still exist but I doubt it, neiman marcus accepts all now I believe. If you have 3 might as well add Discover and round out the group and for good rewards program.
Wallet: FNBO DISC 9.5k, , Chase Freedom 3.3k & Slate 3.3k, AMEX BCP 7.5k & AMEX Hilton Surpass 5.5k & AMEX Zync NPSL, Walmart 3.3k, CapOne AU 1.5k