Going cashless is all about state control of resources and the destruction of privacy. There is no real upside to it, from a liberty perspective.
It will never be fully implemented, IMO. It might on a regulatory level. But that won't stop people from bartering and transacting under the table, whether it's goods for goods, using precious metals, ammo, crypto, or whatever. The segment of society that's willing to work outside draconian over-regulation will continue to exist on many levels.