The first wave of Bitcoin Banks have started to emerge in the form of Bitcoin Treasury companies such as Metaplanet, Twenty One, and MicroStrategy. They are all trying to do one thing: acquire as much BTC as possible and use it to generate returns in whatever way possible for their shareholders.
In short: they are attempting to bridge the gap between the old Fiat system and the new digital asset system by treating Bitcoin as a stock, not as gold.
I don't have a concrete idea of how Bitcoin can be used in finance but I do know that using it to create returns as if it were a stock is unlikely to work in the long term.
I believe that a good use of time is to research and experiment with how a group of individuals can come together a collectively grow a stockpile of bitcoin. Step two would then be how to financialise that or issue a token on top of the Bitcoin whoch could be used everyday in a small geographical area.