Originally Posted by Adelphos

Not really - I hold all three

Amex Plat for benefits, 5x on airfare
Amex Gold for restaurant and grocery spend
CSR for travel spend (and some occasional restaurant spend)

Living in NYC, my travel spend is Uber, taxis, and subway, so getting 3x back on that from CSR is worth it by itself

If it weren't for the credit on all of these cards, it wouldn't make sense to hold them all, but the credits all work very well for me, so I plan to keep all three

Honestly though, if you have an Amex Platinum and are invested in any way in Membership Rewards, Amex Gold is really a no brainer as a companion card, especially if you value the credits