I’m married, 15 years this August. My parents are still married, had their 50th anniversary in 2019. My in-laws are still married, their 50th is coming up.
I don’t really know but I suspect that data would show that children of long-married couples are less likely to get divorced, but that’s just a hunch. I think some instances will result in divorce no matter what the family lives were like. But I also think that marriage requires work and commitment and perhaps having that long-term marriage as your model puts you in a mindset to see the marriage as something you have fully committed to and it would take something genuine momentous to challenge it.