How many of those people are using an LLM other than one supplied by OpenAI?

I do. "Claude" doesn't really tell people much. Anthropic, even less.

Claude is an awful product name, too. I hate telling people that I generally use this thing called "Claude" which "is like ChatGPT but better".

I see what you're trying to say, but I've personally been warned many times by normies "do not use ChatGPT," as if it would be fine if I used Claude instead.