no offense but “family is the people you choose to surround yourself with and love you dearly” will literally ALWAYS be a better theme and a better concept than “love the family you were arbitrarily stuck with because they’re related to you”
because there are some obvious inequalities and injustices in how the traditional family is structured, it’s prone to some well-known abuses, AND even without those, the former model is a lot more appealing in a lot of ways, for the obvious reason that elective affinities are usually going to be a lot more rewarding than accidental, arbitarry ones
BUT
i think a huge amount of the appeal of the latter, and something that would be dangerous to lose, is that it’s a guarantee of warm relations, or at least warm relations of a certain type, that can’t exist in a frame where everything is entirely voluntary.
the idea that EVERYBODY, at least in principle, gets a few people who will be socially pressured to be loyal to them (whether or not they like each other, etc) is an emotional safety net. and, just as there are people who are especially vulnerable to abuses of the family-as-involuntary-loyalty model, there are people who would be especially vulnerable to a world that was more atomistic in terms of emotional and social relations (even assuming there was a decent welfare state, which of course in most historical circumstances there haven’t been.)
as history keeps on going (assuming we don’t kill ourselves) hopefully we’ll develop institutions that balance all these concerns, but i think it’s worth considering what the appeals of all the various models are