I believe bitcoin and banks are well renounced investment platforms but many people prefer bitcoin investment despite is very risky because of high demands and rising price interest and banks on the other hand saves millions of people finances all over the world yet their investment interest is very small but less risky than bitcoin. Which do you preferred your money to be save in as investment? Bitcoin or bank! What's your reason?
Your post became almost confusing from the very girst statement with you having to compare banks and bitcoin in the context of an investment. Banks and exchanges could be seen for a financial institution and as well, an investment but the case is different with bitcoin. Although, bitcoin do serve investment purposes, it is girsgly a currency.
I think what ought to have gone is banks as against wallets or exchanges while, we could always compare or have to bring fiat and bitcoin to context. Them both are the medium of exchange for commodities bought or sold and services rendered.
Hence, why do I have to pick otherwise. I go with bitcoin every other day but, that doesn't mean I won't run some operations with fiat.