I think one benefit would be the individual participants' self-determination (there may be others). It's ok if you don't find my previous example (abusive relationship) convincing, but in the absence of an objection I'll reuse that. If we could look through all the marriages with a 0% chance of divorce, my bet is that we'd find an abnormally high percentage of abusive relationships. I claim that if a match has _no_ chance of divorce, it probably indicates a lack of self-determination for one of the partners.
Taking a step back, it might be clearer to just argue that length / non-divorce is not what people really want from a marriage. I can't speak for everyone, but I want a happy and fulfilling life, and I seek a partnership to the extent that it supports my desire for a happy and fulfilling life. Yes, I do want the partnership to be long, and I don't want to get divorced. Of course I want my marriage to last forever. But this is not my primary goal in marriage. There are many boring or uninteresting people (apologies to them) who I'm sure I could live with forever, that I'd immediately discard as candidates. Alternatively (making the abuse angle more tangible), I also have a lot of international friends and family that would happily find me an international bride who would never divorce me, and would be happy to marry somebody with a US passport. In fact this is a somewhat common offer, though of course they never say it in those words. You can decide for yourself whether that is abuse, but at least I wouldn't feel comfortable with it.