What does Bitcoin "becoming mainstream" look like specifically? The article doesn't offer anything - not even a link.
Let's say it's 1974 and you're writing an article about the desktop computer "becoming mainstream". What does that look like exactly to you? I'm guessing it doesn't look anything like the last 30 years. Not even close.
So how can the author be so confident in asserting that banks must be "on board" for this mainstreaming to happen?
The desktop computer was an attack from below, in the Christenson Innovator's Dilemma sense. It looked and acted exactly like a toy for the first decade of its existence. Most incumbents who saw through that surface illusion were powerless to do anything about it. The one that did (IBM) tried, briefly succeeded, then lost the entire thing.
Banks with their highly touted "experience in facilitating payments" are the very thing Bitcoin has in the crosshairs. Banks losing interest now that the Bitcoin FOMO is gone? Good riddance to them and their AML/KYC bootlicking.