No it isn't.
My grandparents, who were married for 60 years had this mentality. My wife's grandparents, who were married for a similar amount of time, also shared this mentality. My wife's parents still share this mentality (and are obviously completely devoted to one another, which you will notice if you spend about 5 seconds with them). My parents divorced, which has had an incredibly destructive effect on my family, almost certainly as a result of my father's belief that he needed a life that was independent of our family, and that he could somehow live "independently" and still fulfill his role with my mother as the leaders of our family unit.
Go talk to some elderly people: the ones who have been in marriages that have lasted the entire lives are generally completely devoted to one another, and as an extension their families. Unsurprisingly, those families seem to be generally full of happy, healthy people in their own happy, stable relationships.
There is a bizarre (and imo destructive, and toxic) idea that seems to be running through tech especially that devotion to your partner is rooted in "jealousy". It usually leads to "maybe you guys should become polyamorous. What are you jealous?"
And then, predictably, that leads to relationship collapse, heartbreak, and bitterness about 100% of the time. Shocking.