It might be an odd question. So much of the problems in marriages on here seem to have lack of sex as one of the things checked off as a problem in addition to whatever else is going on. I was wondering if there were situations where the marriage had problems but the sex frequency/quality wasn't part of the problem.
If sex wasn't the problem did the marriage still eventually fail or were you able to fix the problems? Did sex cloud your decision making because enough things were bad to end the marriage but sex made it hard to see that? Is good quality sex a sign that things aren't as bad as they appear?
I would say that no sex, can ultimately kill a marriage.
I have been married to the same woman for about 46 years. For a while it was a sex starved marriage that entailed no sex for many many months, at other times there was frequent sex. We worked through our problems with the help of a sex therapist and lots of work and introspection on our part. Sex is a glue. The release of bonding hormones associated with sex, the effect of pheromones, etc. all help to bond two people together into a single marital unit. That is how we are designed and the design has served humanity well for thousands of years.
If nothing else is working in a marriage can sex keep two people together? Once upon a time, when marriage was about survival, yes. Today, probably not for the long term.
Part of the idea of marriage is that two people are united in front of friends and family, who are part of a broader community that is to support that union. When the two have children, then again, the community of friends and family is their to support the union/marriage.
In past history there where times where marriage was about subsistence survival. One spouse hunted while the other gathered and nursed small children. One labored in the farm fields or factory while the other labored in the house. Today, we have better safety nets, so marriage is less about survival.