I have an honest question: what's the cash vs card tip ratio? 99.999% of the time I am not carrying cash and I don't see many (any?) people paying with cash ANYWHERE in the last 10+ years.
Almost no one can give you a good answer because it varies by business type and location.
My business does not involve tips (exactly) but I can tell you that I’ve seen anywhere from 20-40% of money run through my system being in cash, depending on where I am in the country.
in SF I only carry cash for dive bars and the occasional mom n pop diner
NYC here, whole lot of cash still showing up in tip jars - there are still and loads of cash-only places around, from bars, restaurants, to street carts, you name it. JG Melon, for instance, is famously cash only. But so too is the bar around the corner from my apartment (Dynaco, do recommend).
...So people often tend to be carrying cash still.
At this point you are litterally a sucker to pay for anything in cash, because everything is marked-up to cover CC fees, which you get a portion of back in the form of rewards.
Yes, I know some places give cash discounts. Most do not.