Bitcoin is not just for the rich, even when transaction capacity is severely limited. We will have off chain service companies to handle that. Here is how it could work:  A base equity capital. Let's say around 100 bitcoin to cover assets under management 1000 bitcoin. The board and the CEO is made responsible with all their assets (that has been the case in earlier times). Time deposits, let's say in general 3 years. You can pay immediately by transferring your deposits, but you can not immediately withdraw your bitcoins. Loans made to others also timed, say the same, 3 years. The institution keeps a sizeable reserve, let's say 30 %. This will probably be prudent, the market will decide. Due to fractional reserve banking, the money volume should therefore increase by about 3333 (the current system with zero reserve sometimes, would not be possible). There will be no deposit insurance and no bailouts. Sometimes such a bank will fail to pay back, with customers loosing money, and the market will have to keep the industry in check.

Such businesses can produce added value: Interest, loyalty function, price, speed, guarantees, insurance, cool factor, advertisements and so on. They are necessary as long as the blockchain can not serve all transactions. There is no point in working against the appearance of these services, they will exist if they are profitable, and they will expand the bitcoin volume in existence with debt.

The crucial difference is no government sponsored deposit insurance and bailouts. Therefore, it is not the same as the banking fraud going on now.