It is stalker-ish to write up biographies like this about your relatives. It's one thing to write up the weddings and upbeat things like this, but not all families lives are just sunshine and rainbows.

How about that relative of the family who spent time in prison? Grandpa in war? Many old people don't naturally talk about some parts of their lives either because they suffered some injustice like (what as an Eastern European I can think of) their properties taken away by Nazis and Soviets, or they did something they aren't proud of. Are you going to oral history interview/interrogate them to fill in all the gaps? Do you tell them you're going to upload all they say to some servers where who knows who will have access to it?

There are also longlasting family feuds between sides of families, like how one son was tricked out of the inheritance maybe wrongly, maybe he was an ass to his parents. People holding grudges and explaining their life failure and derailment by wrongly or rightly blaming others.

Maybe your aunt is presenting a story that doesn't quite add up when you triangulate it from all OSINT and private sources. Maybe your cousin isn't the daughter of who you think she is. Is it your business?

Even if no such big thing factor in, a biography of a person will be very subjective. You can narrate the same life in many ways so they appear more or less successful or an asshole.

Its fine to keep these things as oral history and memory that fades.

I don't really care about what the regular people who were my great grandparents and their cousins did. Maybe if I could read all the drama, I'd end up hating a bunch of relatives. These things have a natural life cycle of forgetting. That's fine.

Again, it's all well if you live in a family where everyone is nice and everyone was successful and helpful. Otherwise it's a can of worms. Nerds can be a bit blind to this as they just want to play with the toys and treat it like some logic puzzle.