Wechat in China perhaps? Other places have solutions which work well enough to prevent dominance. The combination of Contactless and Faster payments in the UK

Wechat in China perhaps? Other places have solutions which work well enough to prevent dominance. The combination of Contactless and Faster payments in the UK solves most uses cases. You can send payments to people via app instantly. I never carry cash any more. However, this requires everyone to have bank accounts and modern high availability payment/POS infrastructure. Mpesa neatly solves the problem that many people don't have bank accounts, many places don't accept cards (let alone contactless) and there are rolling power outages. However, most people have a mobile phone and you can topup your mpesa account like normal phone credit. It's incredibly accessible.