Not that easy in India anymore for last few years with thinks like Aadhar/PAN card and almost every bank requiring those. Even small time vendors prefer payment using phone apps these days in India.
have also seen a large number of reports of how easy it is to get a fraudulent aadhar card under a fake name, using fabricated paper documents as origins of identity, so that's a possible route
I think the likelihood of this working would also be much higher if someone relocated to a very rural location where the local economy is much more cash based. (eg: if you're from manipur, go find a medium sized town in the hills and don't draw any attention to yourself)