>Bitcoin is an extra payment option in n>0 situations.
And not a payment situation at all in almost all solutions.
"n is small and therefore n is not useful compared to x" is what I'm arguing. You cannot depend on n when the ability to use it as a means of payment is so inconsistent. That goes for any value of n not just Bitcoin.
No one's arguing bitcoin has the same level of adoption as USD for facilitating trade. They're arguing that it has more than zero and that ETH has zero.
Two comments up you argued that having fewer options inherently means you're getting a worse deal than someone with more options. Bitcoin is an extra payment option in n>0 situations. "n is small" is true, and a reasonable point when evaluating the usefulness of bitcoin. "n is small and therefore n is zero" is a little less reasonable argument, but seems to be what you're arguing.