My checking account at a small local bank earns 2.25%, has no annual fee, offers ATM refunds nationwide, has free online bill pay, AND is FDIC insured. I keep less than 10k there. Some people aren't earning that on a CD, which is not liquid.
If the SHTF and I needed even more money, I have access to tens of thousands of dollars via credit cards, some with 2% cash back rewards. I could access these funds during the 3-5 days until the ACH transfer from my brokerage came through and pay it off the next month.
I also keep several hundred in cash in a hiding place, but that's mostly in the rare case I find a Craigslist bargain and must rush out the door!
If I'm physically incapacitated, I have short-term disability insurance through work.
If I'm physically dead, my dependents have life insurance.