In Denmark we have a festival called Skanderborg festival, and they build both your ticket and your cashless payment into the festival bracelet.
You use the bracelet to pay everywhere, and you can add money to it a range of payment methods, from using a visa or similar in their app, to visiting one of the cash places where you can use an atm and then add funds to your bracelet.
It’s easily the best payment experience I’ve ever had at a festival.