I haven't read all 47 (!) pages of this thread. But from a fairly short perusal of the content, I don't see anyone mentioning that banks primary function is to match savers with borrowers. Meaning that they pay a percentage of interest to savers and then charge a higher percentage to people who borrow that money. And they take on the default risk for the loans without (directly) passing that risk on to their depositors.

I'm unaware of how bitcoin eliminates those functions. Imagine a world in which we only had bitcoin. There would still be a desire for some people to save and other people to borrow. Consequently something will emerge that provides those services. I suspect it will look a lot different than today's banks, but I'm guessing that most people will still call it a bank because it will provide all of the functions that they typically associated with a bank.