I don't think that's why Google sat on it. My guess is that it was hubris of the key researchers. They all had these castles in the sky of how it was "supposed

I don't think that's why Google sat on it. My guess is that it was hubris of the key researchers. They all had these castles in the sky of how it was "supposed to work" and then all that is required for quite powerful systems is scaling. Only Ilya seemed to lack hubris and followed the path of scaling. As for their being no moat, we don't know that. We are seeing a number of attempts at replicating GPT3/4 and there has been some success which is indicative that there is no moat, but this is a really new field.