You will increase your chances of getting into a competitive college by applying thru QB if you become a finalist. Somewhere around 35%-40% of applicants become finalists each year.
If you become a finalist you rank 12 schools and have a chance to match to one of them. If you don’t match, as an unmatched finalist, you can apply to any or all of the QB partner schools with the click of a button. Finalists are usually announced around Dec 1, and some schools will still allow unmatched finalists to get into the ED1 and EA pools, even if the deadlines have passed.
You can apply to as many non-QB partner schools as you want. But if you do match, that is binding, even at schools that don’t offer a binding round of admission.