This is ancient wisdom about why two is better than being alone, and it is honest about the reason. Not because two people are always happy together, but because of what happens when one goes down.
If one person falls, the other can reach out and help. The whole design of partnership is aimed at the falling, at the hard season, at the moment one of you cannot get up alone. That is not the exception to marriage. It is the point of it.
Which reframes a struggling marriage. The hard stretch you are in is not proof the partnership failed. It may be the exact moment the partnership was built for, where one of you reaches down for the other.
So before you decide it is over, ask whether it is a falling season, the very thing two are better than one was made for. Reaching out a hand is not weakness. It is the design working.