I don't think that the divorce rate is a good indicator for worsening relationships. I think it is more of a consequence of improvement in the standards of living and women empowerment.
Before that, couples stayed together because they had to. To oversimplify, women needed men to make a living and men needed women to take care of the housework and kids. Now, both men an women can make a living by themselves, housework is less time consuming and there are more options for single parents to take care of kids. So when things go wrong, couples simply break up instead of continuing a bad relationship.
Kid rebellion has always been, that's a normal part of getting to adulthood. But at least now, we avoid hitting them in response.
Things are changing, that's for sure but I think that on average interpersonal relationships have improved too.