Yep. I just use my US driver's license even though I've had permanent residency in Argentina for almost 15 years. I never carry my DNI around. In the USA it's super easy to get your driver's license replaced so I just use that for an ID. Yes, in the supermarket they might ask for ID but I just use my US driver's license. Even if they ask for DNI you'll notice they NEVER fill in your DNI # on the receipt. They leave you to do it and nothing stopping you from writing in fake #.
I just don't see any rational or good reason why I'd carry around my DNI when using credit cards in Argentina.