I will always keep my Amex Platinum because I value lounge access and I actually use all of the credits sans Equinox. Beyond that, I only spend on it if I buy a physical good that I want purchase protection on. I actually think UR points are easier to use. I keep the CSP for that reason. I can't justify holding both the CSR and Platinum even after the credits. I use Skylounges/fly Delta, so canceling the Platinum makes no sense since PP lounges aren't that numerous.

I am actually shifting more towards cashback these days using the BofA setup, although you need $100k with them to make it worth it. But I get a flat 2.65% (3.5% on dining/travel) back with the Premium Rewards card; 5.25%/3.5% on online shopping and Costco with the CCR. I use the Amazon Prime card for WFM and Amazon and Costco Citi for 4% off gas. I am not sure how long I'll go with cash back, but I amassed more than 600k MR/100k UR points because I have not been traveling.

But if you do travel often, I'd keek accumulating points. It all depends on which airlines are in your home airport more than anything else.