I’m normally plastic all the way too but as you’ll need cash for most purchases in Argentina anyway, it’s not that disruptive (unlike in the US/UK where having to get cash for a transaction becomes a special effort). Also, you still know how much it’s going to cost beforehand, so can prepare the appropriate notes during the ride and just hand it to them while leaving. Helped by the small denomination of notes, I was always able to get it close enough to be comfortable with declining change and leaving immediately.

Your post history suggests you are American which means you won’t even need to pay ATM withdrawal fees given the right bank cards