So I have a United Explorer card, which gives 2x on United Purchases. Am I right in thinking that now I have a Platinum there's literally no reason to put United charges on there instead of the 5x AmEx points?? And maybe no reason to keep the card at all (the two club passes a year are handy tho). The 500 PQP / $15k also help at my level of travel.

(Yes I realize this is a super basic question, and 5x is clearly more than 2x, but want to be sure I'm not missing anything here).