The fact that love exists would only mean people would be more civil when they disagree with one another.
Being in love doesn't mean your perception of a problem changes or that there are no incompatibility issues.
There is no amount of "work" or "communication" that can overcome being with someone who simply does not want what you want for the relationship. Exp. One person wants children the other doesn't.
People marry either hoping their mate will "change" or believing they won't. To some extent both assertions are unrealistic.
Over time "we're either growing together" or "growing apart".
Generally speaking compatibility trumps compromise!
Like attracts like and opposites attract divorce attorneys.
There still would be couples who decide it's best to just walk away.