The by-laws are less significant but they aren’t insignificant. They work, or should work, hand in hand. If your by-laws demand a certain level of noise insulation in your flooring and the law demands that reseidents don’t be disturbed, the Tribunal has an easy avenue for resolution (Muppetry notwithstanding).
The significance of by-laws is that they deal with local conditions in a detailed way that can’t be dictated by state laws. So it’s not one or the other, except where the by-laws of the building are clearly unfair or inadequate.