Consider Marriage Story (2019). While primarily about divorce, Noah Baumbach’s masterpiece is a brutal autopsy of what happens to a child (and the concept of home) when parents remarry other people. The film’s most agonizing scenes aren't the screaming matches, but the quiet moments where young Henry shuttles between his mother’s chaotic LA apartment and his father’s sparse New York loft, now populated by new partners and new rules. The blended family here is not a unit yet; it is a negotiation.
The gold standard here is The Meyerowitz Stories (New and Selected) (2017). Noah Baumbach (again) crafts a portrait of half-siblings (Adam Sandler, Ben Stiller, and Elizabeth Marvel) who share a difficult artist father. They are technically siblings, but their different mothers and varying degrees of neglect mean they are simultaneously intimate and alien. The film’s genius lies in showing how blended families often produce adults who are strangers to each other, forced to reconcile shared blood with wildly different memories.
Similarly, Capernaum (2018), the Lebanese drama, shows a child suing his parents for neglect. His parents have remarried and had more children, creating a sprawling, impoverished blended unit where children are treated as economic burdens. The film is a devastating critique of the idea that any family, blended or otherwise, is inherently good just because it exists.