It is a good article worth reading.

Basically, it says the bank gives me no interest on my deposit, and there is a risk that it fails, so the risk-reward equation does not work.  It does not consider the ease of access etc as a reward.

By the same token, BTC also fails in risk-reward equation.  There is a risk that your bitcoins may be stolen, lost etc but the (financial) reward is zero.  You don't earn interest on bitcoins.