Mortgage interest, dependents and investing in real estate (depending) will help, absolutely, but won’t be the same as for example, doing the max amount ($20k) in traditional 401k. Filling jointly will also be better for both of you, since the deduction will be higher. With the mortgage interest, dependents it will lower your standard deduction and you will have a higher refund, depending on how you manage your W2. Filing jointly has more benefits than disadvantages.