The upstream models weren't built by god, they were built by distilling the world's knowledge and cultural products.
If OpenAI/Anthropic stop doing it there's no reason to believe someone else won't. Or that we won't come up with a different approach.
> they were built by distilling the world's knowledge and cultural products
... and a bunch of RLHF and proprietary training data etc etc, but regardless, this is still an exceptionally expensive process, that someone somewhere is paying for.