Suica = a response time of under 200 ms, versus around 500 ms for contactless Visa.
I wonder how well credit cards cope with Tokyo’s rush hour. Suica’s response time was specifically designed to handle the sheer volume of passengers passing through the ticket gates at Shinjuku Station during rush hour.
I really wish JR East had built a better back-end system and financial infrastructure around Suica. It could have become an international standard.