Trump prides himself in honoring his commitments, so I don’t know where you’re coming from. As for marriage, it’s be on the down slope for the last sixty years. Used to be living together was called shacking up and not done in polite society. Nowadays is seems to be de rigueur. Trump didn’t cause that and can’t fix it.
He didn't honor his commitments to his first 2 wives when he publicly cheated on them, or honor the commitments of other women to their husbands when he committed adultery with them. He has a history of not honoring his commitments in business - just ask the illegal Polish immigrants who were cheated out out pay and retirement benefits working on Trump Tower ( you may not agree, but a court did to the tune of a million dollars or so). Trump claims he honors his commitments, but his life demonstrates the opposite - so you believe what he says, and not what he does...