the cost ?
bitcoin is free for everyone ... miner do the security job and transaction verification.
This is something people keep ignoring. With centralized systems, all of the costs are taken care of by a company spending tens of millions a year. With P2P (BTC, etc.) it is spread out among the users. This is a HUGE cost reduction.
Companies do still pay for legal teams, dealing with compliance with laws, etc., but the mining process cuts back on a LOT of costs otherwise seen. Especially in the fraud department.
But I feel there might be a problem with the miners themselves. The current trend is that a few entities own a very large amount of the network hashrate. That kind of centralization beats the very idea of decentralization that bitcoin was meant to be. And if you have more and more businesses accepting bitcoin,and there is no government access at all to these entities,they have effectively become the new custodians of your money. I think that's more scary than government control because of the utter lack of accountability.