What prevents people from just using Google, who can build AI stuff into their existing massive search/ads/video/email/browser infrastructure?
Normal, non-technical users can't tell the difference between these models at all, so their usage numbers are highly dependent on marketing. Google has massive distribution with world-wide brands that people already know, trust, and pay for, especially in enterprise.
Google doesn't have to go to the private markets to raise capital, they can spend as much of their own money as they like to market the living hell out of this stuff, just like they did with Chrome. The clock is running on OpenAI. At some point OpenAI's investors are going to want their money back.
I'm not saying Google is going to win, but if I had to bet on which company's money runs out faster, I'm not betting against Google.