The most important advantage of bitcoin is that only you use it and nobody else. Whereas bank uses the money on your account and in case of any problem you will not be able to withdraw your money from the account at the right moment for you. Also you can transfer bitcoin anywhere and anytime, regardless of the schedule of work and holidays, as it is in the bank.
Not wanting to be rude, the usage of our funds by the bank is not illegal per se, some banks do as you cited. And that is why we periodically get some dividends from time to time. But the part where our money could not be withdrawn should we wish too is not so true unless in the event of a technical bank issue or chaotic events caused by war, disaster or economic crisis.
Though i do agree that the bitcoin you have is rest assured to serve you alone at any point of time and none have any access to is except you alone. Perhaps it is in this sense of security that bitcoin pegged a clear edge over banks.
