OpenAI is an API you put text into and get text out of. As soon as someone makes a better model, customers can easily swap out OpenAI. In fact they are probably already doing so, trying out different models or optimizing for cost.

The backing isn’t a moat. They can outspend rivals and maintain a lead for now, but their model is likely being extensively reverse engineered, I highly doubt they are years ahead of rivals.

Backers want to cash out eventually, there’s not going to be any point where OpenAI is going to crowd out other market participants.

Lastly, OpenAI doesn’t have the users. Google, Amazon, Jira, enterprise_product_foo has the users. All are frantically building context rich AI widgets within their own applications. The mega cos will use their own models, others will find they can use an open source model with the right context does just fine, even if not as powerful as the best model out there.