Comment by kenjackson

The three biggest things I’ve seen cause estrangement are:

1. Coming out. I suspect that gay people always existed, but just didn’t come out.

2. Interracial relationships. Far less common in the past. And society doesn’t view them as negatively now, which changes the power balance.

3. Parental affairs. I suspect this is the one that always happened, but people just lived with it more.

From my anecdotal list the problems are actually new. And except for the third, likely to get better.