I am not a banker, but I believe banks have to have assets to cover all of their deposits, and more, by law.

Fractional reserve is about how they have to have a small fraction of liquid stuff to deal with withdrawals.

The usual idea of fractional reserve banking people have on the internet is a myth, it would be an insolvent bank, I believe.

And banks don't have to have just $1 in assets for every $1 deposited, but they have to have a little more in case some of their loans go bad.