I suspect most people are not using bank accounts as one account among many for financial diversification - the bank account is their sole account. My question

I suspect most people are not using bank accounts as one account among many for financial diversification - the bank account is their sole account. My question could have been more specific - I see little reason to prefer a bank to fidelity. It is government insured up to 1.25M though - so I think the risk is minimal short of government collapse.