My wife's dad is bad for this. In the 90s he split from his wife and moved in with her best pal. One daughter, who was disabled, stayed with her mum. He never spoke to her again. The youngest daughter took the situation badly and, at the age of 15 or 16, shouted at her dad. He never spoke to her again.
He did speak to my wife until 2019. By this stage my wife's youngest sister had reached out a couple of times. She asked my wife if she would ask him one last time if he would speak to her. A intermediary. He said he would speak to his wife (he married his first wife's pal over 20 years ago). She came back to my wife and said no.
The they ghosted us. My wife, the kids, everyone.
So, of his 4 kids he only speaks to his son once or twice a year. But he is apparently a great dad and grandad to his wife's kids and their families.
He had a heart attack last year. Did his wife phone us to let us know? Did she f**k.
When he dies it'll be a quiet funeral. I doubt any of his kids will go.