Operation Choke Point was run by the government within the framework of the existing banking sector. It was enacted by DoJ (one part of the government) then:
"In August 2014, U.S. Representative Blaine Luetkemeyer introduced a bill that would limit law enforcement's ability to restrict access to the banking system as a response against Operation Choke Point.[12]"
So it was stopped by Congress, another part of government.
The existence or non-existence of cash wouldn't have made a difference to the ability of pay day lenders or firearms dealers to continue operating because I'm pretty sure they wouldn't be able to get access to cash to conduct their business unless they had bank accounts!
My point is that a government supplied electronic payment system would make no difference to the ability of a government to engage in anything more or less nefarious than they can already do, and the legislative process is capable of dealing with that (and if it's not, cash won't save you either).