Fractional-reserve banking isn't anything else besides transfer of money from the people at large to bankers.
It has been argued that fractional-reserve banking serves a purpose in making new funds available out of no one's pocket for lending and thus directing resources to productive borrowers. This financing method is preferrable to the more conservative way of borrowing funds directly from a saver and then using that to lend to others because it uses new money, money not tied to anyone else before, and thus it's cheaper and involves less friction.
Instead, what happens is that someone must at all times be the owner of each money. So when banks use their power of generating fractional-reserve funds, they are creating new money and they are the owners – at this point, a theft occurs from the public at large to them – and then they proceed to lend their own money. From this description it is clear that the fact that bank customers have previously deposited their own funds in the banks' vaults have no direct relation with the fact that banks created money afterwards, there's only a legal relation and the fact that banks may need cash deposited by its customers to redeem borrowers claims, but even that wouldn't be necessary if banks were allowed to print their own cash.