Yeah, he'd have to start his own credit card company. Tough to do. Lots of international legal and regulatory hurdles.
But a credit card company is useless without support from banks. So he'd have to start his own bank. Again, A LOT of legal and regulatory hurdles. Plus, he'd need depositors.
The above is hard enough, but there's an additional problem. The entire woke establishment -- EU, Federal Reserve, ADL, SPLC, World Bank, NGOs, etc. -- will wage war on him from the top. While Antifa, BLM, etc., will harass from the bottom.
That's why this has failed before.
I read of some "free speech" payment processor that went online a while back. It failed because Antifa organized a campaign to buy lots of goods with it, then demanded charge backs, saying their card was used fraudulently, or that the goods were defective, or whatever. This company was deluged with charge-backs. Forced them out of business.
I tried to google info on it. All I found was this (I don't know if it relates to the above): New alt-right payment processor. How long to burn it down?
Any free speech payment processor will be seen as "fascist" and will be faced with organized opposition from above and from below.
Gab has been hit with everything the Satanists have come up with and Gab still stands.