That's not a real moat except in one sense: if it is really expensive to get to the level to compete, and you know a competitive market would bring margins near zero, then no competitor may actually step up. We see this in off-patent drugs, where it may have 200X margins but no competitor will go through the FDA manufacturing reapproval process because they won't actually get those margins if they begin competing on price, and then the sunk cost of getting to the competitive level isn't worth anything for them.

I think OpenAI's big moats are in userbase feedback and just proprietary trade knowledge after they stopped sharing model details. They may have made some exclusive data source deals with book/textbook and other publishers, though it isn't clear a license is actually needed for that until things work through the courts.