Bitcoin is my bank.
bank holds assets. Assets includes tangible things that are other than properties. Example would be Central bank
bank also makes investment. Example of this would be JP Morgan.
When prices are high, you can purchase things with bitcoin. Example includes gold, silver, education, training, and hosting services.
When prices are low, you can buy back with bitcoin.
as an user of Bitcoin you need to realize Bitcoin is your bank, but it is not an bank that someone manages it for you so you just get money when you like. The bank you were think of are the North Korean bank where Royal-Court system economy are in practice. This is, however different than what Bitcoin can offer to individual and entities.
with that said, Hopefully you understand there is an distinction between royal court economy banking and banking (which includes investments and management of custodianship to various types of liquid assets)