If you are following the Gemara’s standard then she actually has no access no the bank accounts. In fact, even when she makes money she is supposed to hand it over to him. This is because the financial responsibility is his. He is Mechuyav to give her money for all her needs.
This is a partnership and she has a right to say that she’ll rather take care of her own expenses, in which case she keeps her wages and he doesn’t have to give her money for her needs.
Most families these days treat it like equal partners while one is more in charge of the checkbook.
Someone who doesn’t expend much effort on making the money can’t grasp the issue with spending what you have. On the other hand, it is easy to dismiss someone else’s needs or strong desires as extra and unnecessary. When both of you are more aware of the other’s inner feelings you will be able to make more informed decisions.