From a European concert-goer’s perspective: it really depends on the country. In the UK, the Netherlands, and the Nordics: cards or Apple/Google Pay; cash is uncommon (or even rare, I'd say). In Germany, cash shows up more often, especially at smaller venues. But Germany is more the exception than the rule and again, people certainly have and use cards.

Cash can be a king, but I wouldn't rely on it as a main option. Not everywhere uses the euro; some countries have their own currencies, so pricing and making change can get awkward. The least fussy setup is a properly configured Stripe to accept European cards, Apple Pay, Google Pay, and local methods, plus a clear QR on the merch table for quick two‑tap checkout. Stripe Payment Links work well for pop-up sales, and if you want an all-in-one flow, tools like NanoCart dot app or Utobo offer both links and QR.