> Besides, it's not like you can boycott Mastercard or VISA
Most countries have some kinds of domestic transaction systems, or at least a more local credit card brand. They're also usually instant. It's more or less an US-only situation that people use Visa/Mastercard even for intranational stuff.
Most countries I've been to use Visa as their most common card. Living in a major Asian country and every bank and credit card company offers Visa as their main card as well.
China is kind of an outlier with Union Pay, and while a large number of countries offer their own alternatives, I'd say most are Visa-first. Apparently about 37% of cards around the world are Visa, so that's a huge chunk. JCB is the biggest non-Chinese non-American provider by revenue, and even they're a minor player in their home country.
That is absolutely false. In pretty much any western country, you're forced to use the VISA network, even for debit cards. Take a closer look at your locally branded card, and you'll almost certainly see a VISA log tucked away somewhere.
Depends, in France for instance all the cards are dual "VISA/Mastercard" and "CB ". They will use CB in france and use the partner network in foreign countries.