The assertion that central banking and corporate control is capitalist is naive at best. Central banking along with any form of central planning is the antithesis of pure capitalism where free markets rule and central planning is just a form of communism. Secondly linking bitcoin/decentralised cryptocurrency to some globalized central monetary system is just plain wrong. Bitcoin is not controlled by any one major country/private party and is deflationary in nature. Your concern of a global centralised digital currency is well founded though but it most certainly will not be Bitcoin as bitcoin by nature goes against what the central planners hope to achieve.
RE: Are we on the brink of a cashless society?