I'm German, but in Bogota. Famously, Germany has a strong affinity to cash, credit cards have seen a slow adoption, and the cultural aversion to debt makes them still a bit "off", though they are accepted in the majority of places. More common are bank debit cards, but every business will accept cash. It's been historically common to pay for used cars in cash, out of a mix of spending limits on cards and a paranoia that this should be a transaction of equal immediacy.

In Bogota, well, much of the country is unbanked or underbanked. You can pay ANYTHING in cash through the ubiquitous "cash payment" officies (like Pagatodo). You give them a reference number the service gave you, and cash, and they mark your bill paid. This works for a five-dollar power bill, internet bill, evenfor as a thousand-dollar flight you booked online.

There's a paypal-like phone app, Nequi, that almost every colombian has as well, far more common than credir cards. While big stores and restaurants will accept cards, a small (and not licensed) street vendor will often have a QR code to pay by Nequi. This needs no special equipment and no special permits, apparently.

There are many signs "cash only", and many signs "cash and nequi, no cards", especially in small stores.

Nequi, however, is not available to foreigners, even to those who live in Colombia with permits. Cash is everywhere.