That's the reason you need different cards for different purposes.

I use cards 7 days a week unless the merchant doesn't accept cards. For e.g. I bought RM 5 broccoli from Giant, I tapped with my MBB VS. Even if I buy McD's Sundae Cone, I tap with HLB MACH.
In fact, I seldom go out shopping with AmEx on weekends. I'm lazy to go out, I use it to pay bills.
I don't have much cash with me. I still like the life in China, where I lived cashless there. Just my mobile phone and scanned QR. Though, this trend is yet to boom here, but I already appreciate using cards and maximize my cash back.
That said, my MasterCard that comes with M2Cards is locked in drawer. Again, if you are only as crazy as me who likes to use cards and I have a lot of cards. If you want to keep it simple, then that's different story.