PayPal only supports tap-to-pay in Germany. Curve Pay supports tap-to-pay on GrapheneOS in the UK and the whole European Economic Area. Many European banks have working tap-to-pay too, and the trend of those replacing their independent system with Google Pay has subsided. It's mostly a non-issue in Europe but there aren't similar alternatives for most of the world. Japan does have their own alternative which works on GrapheneOS with Japanese models of Pixels.
Klarna also offers tap to pay in their app, at least in Germany. Not sure whether that's the case in the rest of Europe or elsewhere.