I agree that you're probably seeing people out and about who may look fine but behind closed doors are not.
But, hey, there are many people who are fine and have the dream. There's no getting around that. We didn't get the good family and that hurts.
Ime, just like an abusive romantic relationship, I went back in the hope things had improved. They were MUCH worse. Whether because my tolerance was much lower having had a few years of peace; or whether they had stored up those few years of toxicity and I got it in one go. Who can tell.
These days I don't hanker after them. I luxuriate in my freedom, it is a constant source of joy that I am free from them. As dazzling as their social events look, I know from experience it would be a day of being mercilessly bashed. In all honesty, it holds no appeal.
BUT that doesn't mean I don't have a squashed feeling that I am alone with no family. I cant know if I'd feel the same if they were all dead. I am currently going through a serious health crisis and, oh, I could do with family during the rough times. Friends, though lovely, aren't the same.
Imo it is like a bereavement and one goes through very real stages of grief for some time. One can't hurry grief, it takes its time. Regardless how bad things get I am never tempted to go back. I just wish I'd been dealt a better hand. That's the sum of it.
There is an org called Stand Alone which supports people in our position. I've not had much joy getting along to their events but do take a look.