If corporations start paying entirely via stablecoins and corporate cards, who actually controls money then?

With stablecoins settling instantly and corporate cards programmable by code, it feels like money is becoming software. If companies start paying salaries, vendors, and taxes this way, who actually controls the system? Banks, card networks, governments, blockchains, or the companies issuing the stablecoins? Does this shift reduce power concentration or just move it somewhere else? How will it effect the liquidity of cash in the market? and will it also improve the transactions which were earlier done only in small amounts?