To create an OpenRouter account, you have to supply a phone number. Neither Anthropic or OpenAI required this. This prevents privacy aware users from signing up.
Anthropic request ID verification and OpenAI requires phone number in Europe. I don't know about other parts of the world, but I don't see any issues with OpenRouter.
Again, neither Anthropic or OpenAI asked for PII. Only my payment information. Open Router requires a phone to get an account, which is why I'll never have one.