We keep a fair amount of cushion earning virtually no interest, because we're already FIRE. Sure, it's losing to inflation, but it's a tiny amount of our TNW. We're renovating a condo right now and it's nice not to worry about juggling payments.
We also had to replace the A/C in a rental rather unexpectedly recently. It was $5k and paying the bill was no big deal.
Most of my career was in commission sales, paid monthly. I got used to living on last month's (or three months ago's) money. I would accumulate too much money in my checking account, then move it into investments, because that's what worked for me. Somewhat sub-optimal according to many sources, but we're FatFIRE now and loving life.