Hm, there are a bunch of topics that cover this on BSE, e.g. https://bitcoin.stackexchange.com/a/38998/5406. The issue seems to be that the chat is limited to generate a response on basis of the first six search results to prevent hallucinations. There is not a good result in the first six hits for this exact search phrase. I could replicate your results, but also get better answers by asking slightly differently.

Murch

bitcoin

ChatBTC

Roll

Not that great:

Q: Exactly how many bitcoins will ever be mined?

> Holocat
> 
> The total number of bitcoins that will ever be mined is capped at 21 million. This information is mentioned in the excerpts provided, specifically noting that "the number of Bitcoin that will ever be mined is capped at 21 million." The document also discusses the issue of bitcoins being lost forever due to private keys being unknown, but this does not change the maximum cap of bitcoins that can be mined.

I was expecting it to know the nuances of the system and the history of it.