It is ridiculous to assume that the overhead from regulation/staff/legal is more efficient than electricity and math. Banks and governments will never be able to compete with bitcoin as they have legal obligations which carries counterparty risk. Bitcoin is soveriegn and allows for regulatory arbitrage. The OP is missing the mark by ignoring the truly powerful aspects of bitcoin which can't and won't be replicated by banks - Proof of work, No KYC = Privacy and less risk of identity theft, and an immutable blockchain.

Do you really assume that Bank blockchains will be immutable even when legislators , regulators and judges demand a tx reversal?

It is likely the OP is merely trying to scare some weak hands so he can buy cheap bitcoins before the next bubble.