This is my understanding as well. If GPT made money the companies that run them would be publicly traded?
Furthermore, companies which are publicly traded show that overall the products are not economical. Meta and MSFT are great examples of this, though they have recently seen opposite sides of investors appraising their results. Notably, OpenAI and MSFT are more closely linked than any other Mag7 companies with an AI startup.
https://www.forbes.com/sites/phoebeliu/2025/11/10/openai-spe...
Going public is not a trivial thing for a company to do. You may want to bring in additional facts to support your thesis.
Going public also brings with it a lot of pesky reporting requirements and challenges. If it wasn't for the benefit of liquidity for shareholders, "nobody" would go public. If the bigger shareholders can get enough liquidity from private sales, or have a long enough time horizon, there's very little to be gained from going public.