alt Hacker NewsThis would still rely on Visa/MasterCard allowing dual-branded credit cards for overseas transactions, which isn't a very common arrangement. The only market that has this is in Asia where there are UnionPay + Visa/MasterCard dual branded cards and I suspect that the reason they allow this is because the market is huge, especially compared to Canada.
Also Interac does not do online transactions outside of some very specific merchants that take Apple/Google Pay transactions. This is how Interac reduces fraud risk, which is why interchange rates for Interac are so low.
You can do this in multiple steps. Start with a credit card usable only with Canadian merchants, which will cover a great majority of transactions of a great majority of Canadians. I'll have an MC for travel and the ordering from non-Canadian merchants, and this Canadian credit card for the other 95% of my expenses. If a significant percentage of Canadians have such a card, major non-Canadian services will add it as a payment option (e.g. ChatGPT or Claude). Then you branch out by either joining or co-branding with the EU credit card company if such a company succeeds.
A world with a patchwork of payments processing options will look different for travel and business, in some ways worse, but such is life in a "multipolar world" which the Americans elected their leadership to conjure up.