I wish you would just write what you think. It would really help discussion. I assume you are not literally arguing that fractional reserve banking is how things work, but it's hard to tell what you are arguing.

I know about central bank reserves. It's not fractional reserve banking, though. It's basically just regulation, but regulation done in the language of money, which banks (and any 5 year old) can understand.

Banks have many reasons for attracting deposits. Not least of which to get customers "on board" such that they might buy other financial services. But yeah, they also need to stay on the right side of regulation, or not run out of central bank reserves, if you prefer to think of it that way.

Ultimately it's all fake. Whether you think of it as "reserves" (that don't really exist, of course), or regulation is up to you. It's ultimately just a bunch of IOUs but raised up about ten levels of abstraction.

Anyway, the whole thing is incredibly complex and nobody understands the whole thing. I did think the commenter was referring to fractional reserve banking, but they might have meant central bank reserves, I don't know.