There's an argument for putting Marriott spend on a Marriott card at 6x since it's bonused. AMEX occasionally throws some promos at their card where it's not just 2x for spend (right now it's 7500 MR for 2k spend on a Bonvoy Business, which is a fairly decent boost, last year they had some for the Brilliant). Also right now the Brilliant has 6x for dining.

But 2x when you can buy points at regular intervals at less than a penny a point and 2% cashback cards are free is just... bad.