What makes you think that the people involved in the disruption of the banks won't partake in the same shenanigans? Do you think "bankers" are inherently evil, while their replacements will be inherently good? The Bitcoin world says otherwise. "Tech people" are stealing people's money left and right.
>If the banks are "too big to jail/fail" then maybe we should make them smaller...
Sure, and then we'll let all the pseudo-government-controlled banks in say, China, or even Canada do all the large-scale banking business globally.
The business of banking is vastly larger than cheqing accounts and ridiculous ATM fees that people like us deal with day to day and complain about. That's why the industry is heavily regulated, and why the banks are so large, and why the local credit union in Podunk isn't underwriting the Facebook IPO. It's also why some SV startup isn't going to ride in and up-end the industry without itself becoming some financial behemoth that needs to be regulated.