I don't know that OpenAI specifically is the weak link but this definitely adds to the argument that the entire sector is a wash with the same three or four companies passing around the same $50B over and over. OpenAI is just the link that seems most likely to break first.
If tomorrow Claude pricing changes and they start charging real API costs like 2000+ USD, and there is another service: "NotReallyClaude" that is a bit less good but 200 USD, then what would you do ?