The person you were replying to was not talking about SF but you specifically called out SF so you were implying that

The thread started with "$200 is a lot for most of the world", the person I was replying to said "no it's not, now anyone can sell to billions of people", and I said "company success being concentrated in SF shows that that's not true".

I didn't say "only SF can afford $200/mo".

"I guess all those people who live in not-SF just can't be bothered to succeed!"

I explained it in my previous comment, I'm not going to explain it more than that.

Again, if you think that only successful companies are in SF you live in a bubble.