I think families are complicated and it's very hard to judge based on what little you've seen of theirs.
DH and I are estranged from his parents and eldest sibling, for very good reasons, but we are the ones cut out by the immediate family.
I think it's because families with issues are secretive.
DH's other siblings weren't happy when we went no contact and they did make it known that our decision was making their lives harder.
But they were still reasonably okay with us until we stopped keeping the estrangement and the reasons for it a secret.
When I started to openly talk about what PILs had done to me outside of the family, they were furious with me for discussing it "with strangers" and suddenly I was responsible for tearing their family apart.
I had to have three sets of therapy to help me deal with everything DH's family have done. DH has had two sets of therapy and still needs more.
They used to worst time of our life to abuse us, when we were grieving and least able to defend ourselves. Then raged about it when we did what we needed to do to heal.
But they have come together now, there is an engagement in the family and I suspect we won't even be invited to the wedding. But if we are, and if we go, we will be the people sitting at a table alone while others wonder just what awful things we did.
What we did was set a boundary after two of our children died, PILs were verbally and emotionally abusive about it, and then stalked me and DS while DH was away, to force me to allow them to continue as they wished.
DH for many years refused to talk about the way they have treated him since birth, but can now recognise that all of FILs family and part of MILs have walked away, cut themselves off, or been cut off, due to his parents behaviour.
His siblings have witnessed how we've been treated and decided it's safer to stay on PILs side than stick their own necks out and face what we've been put through since the day we finally set and enforced a firm boundary on what we would no longer allow.