Being your own bank is just one side of it, the other side which can not be ignored is still there, that is, exchange that btc into cash for spending, btc is not widely accepted and so the need to exchange to fiat through the bank still very much needed.
For now bank is the necessary evil which we have to deal with until such time btc becomes acceptable in all part of the world.
In other words, bitcoin for now is only just an alternative to the real banks or to the fiats. Or maybe it will remain this way forever? Since, it's almost impossible to use your btc in most of the common services that we know locally to the fact that bitcoin is digital and there are some things which can work perfectly without having the need of internet, computers, mobile phones and other gadgets.
You can always try to use your btc for buying dry goods online since there are many shops now are accepting a bitcoin. In terms of exchanging our btc into fiat. There are places that you can do it without needing to go to an actual bank, if you are allergic with their presence.