One question that's come up for me a number of times in the past 2 years or so is "how permanent does a healthy relationship need to be?" Traditional values sug

One question that's come up for me a number of times in the past 2 years or so is "how permanent does a healthy relationship need to be?" Traditional values suggest that "'til death do us part" is the desired level of permanence, but as a society (even preceding online dating) we've been moving away from that idea. More specifically, it used to be somewhat taboo for a widow to remarry, but now it's almost expected that a young widow will eventually find another spouse. As our expected lifespan grows, are the costs and benefits of fully committing to a single person changing? As far as kids are concerned, you want a marriage to last long enough to get the kids to a certain degree of autonomy, but is that level changing too (which is interesting, because it might seem that kids are taking longer to gain autonomy compared to a hundred years ago). But we all expect to become grandparents. This is clearly beyond the point where you need to commit to a spouse for childhood reasons. Is our changing environment enough to justify an expectation that marriage should no longer be permanent?