When interest rates were near 0% between 2008 through 2020, it made a negligible difference to pay bills from checkings or savings. But with savings rates hovering around 5%, it's worth about $1,000 per year for the $20k we keep in cash for paying bills.
I made a simple system for paying bills that would follow interest rates, and reduces taxes on the earned interest.
As a California resident, Fidelity makes this easy with FDLXX:
The Adviser normally invests at least 99.5% of the fund's total assets in cash and U.S. Treasury securities. Potentially entering into reverse repurchase agreements. Normally investing in securities whose interest is exempt from state and local income taxes.
Residents in other states can find equivalents easily with a search for "tax exempt money market funds". A nice feature of this particular fund is it can auto-liquidate, meaning that payments and transfers will automatically sell this fund as needed. We do have to manually purchase this fund because it's not available as a core position. The core positions SPAXX and FZFXX also yield around ~5% currently, but my understanding is they're federal and state taxable, which would hit us with a ~22% and ~8% tax bill respectively; Eating away $300 a year in interest. There are state specific municipal bond funds that are federal and state tax exempt, but current yields net tax savings are below our marginal tax brackets. TurboTax has a checkbox to enter this information.
We're not holding additional cash to take advantage of higher yields because we are sticking with our investing strategy, but it's a nice bonus / inflation offset to earn a little on cash we need for our day-to-day expenses. This approach doesn't require chasing new account bonuses, or promotional interest rates with caveats. When rates decrease, we'll lose some interest, but it's a good set-and-forget system.