It doesn’t matter that it was a name collision with Stripe the payment processor. EVs were not designed to resolve name collisions. They were not even intended to attest that a business is legitimate.
What matters is that Ian had to register a company to get that EV. Which means that if he had actually tried to scam people with it, the police would have a nice paper trail back to him.
The paper trail is the deterrent. All the EV does is attest to the existence of a paper trail.
Name collisions are not a problem in general. There are other people in the U.S with the same first and last name as me. There are thousands of restaurants called “McDonalds” that all look the same even though they are owned by different companies.
It’s a solved problem. It is solved with legal documentation, like taxpayer ID numbers, articles of incorporation and payment records. The sole purpose of EV and OV certs is to cryptographically connect your browser to those.