[pjg]

There is nothing preventing PIX from going global (just like VISA/MC). If you look at the history of domestic systems e.g. China Unipay, India UPI/Rupay, Japan JCB they started off as local systems and went global.

Japan JCB is Internationally accepted. China Unipay is also considerably "international" i.e. internationally accepted and India's UPI/Rupay card is adding new countries at a fast clip. The reason most people "don't know" whether they can pay with China Unipay or India's Rupay is because they are not advertised with the same logos as VISA/MC on acceptance sites.

However both China Unipay and India's Rupay through their partnership with Discover Card (now owned by CapitalOne ) are accepted anywhere Discover card is accepted

The place where these "domestic" systems haven't quite measured up to VISA/MC is the issuing side i.e. the entities controlling these systems currently do not allow foreign banks to issue cards with their logos or use their network to settle the transactions. If you're in the US, you may not get a Unipay or Rupay card from a local bank. There are multiple reasons for that, some strategic some political.

It will be interesting to see how they evolve over time. In spite of the exponential rise of PIX , UPI and Unipay, VISA and MC themselves have been doing remarkably well in the past 10-20 years. Unlikely either of them will go belly up.