Commitment to life long duration…well it can and and it can’t. The Same holds true for Sacramental marriages in many cases.
The difference is the approach to marriage (hopefully). Think of marriage as a verb rather than a noun.
In a sacramental marriage, the couple places Christ at the center of it. (you obviously don’t have that same level of interaction with a non-sacramental marriage.) That means that each spouse relies on each other THROUGH Christ. A Sacramental marriage is therefore lived as a single body through Christ.
As such, they are truly one body both spritually and physically. When they maintain that focus it is as difficult to separate like it would for anyone individual to cut off an appendage. The Sacramental bond through Christ is that strong.
But we do have human failings, and couples will falter as a result. It is those times that marriages are endangered because they stop operating through Christ for whatever reasons. That doesn’t mean that the commitment will fail but it is much more difficult to maintain because the focal point becomes misplaced.
A sacramental marriage flourishes in a very special and unique way when that focus on Christ is maintained and lived jointly.
Non sacramental marriages can maintain their commitment but that special grace imparted to the spouses is not there in it’s fullness.
So you can have commitments and divorces either way, but only a sacramental marriage benefits from the aid of Christ’s grace because the spouses make a choice to accept it.