> I don't think this is necessarily that the advice is getting worse.
> but I don't think that telling people to break up more is less accurate advice.
Those are subjective determinations based on personal experience. But breaking up more without addressing the underlying issues is likely to cause steadily worsening problems at both individual and societal scales. I'm not a mental health professional, but I can see several problems with this approach.
The first is that the determination of the issue is really tricky and needs careful work. The partner who seems abusive may not always be the actual perpetrator. They may be displaying stress response to hidden and chronic abuse by the other partner. For example, a short temper may be caused by anxiety about being emotionally abused. Such manipulative discrediting of the victim may even be a habitual behavior rather than a deliberate one. And it's more common than you'd imagine. When you support the second partner based on a flawed judgment, you're reaffirming their toxic behavior, while worsening the self image of the victim that has already been damaged by gaslighting.
Another issue is the degrading empathy. All relationships, even business deals, are based on sacrifices and compromises meant to bring you benefits in the long term. Stable long term romantic/marital relationships have benefits that far outweigh the sacrifices one usually has to make. But the evolving public discourse, especially those on r/AITA, is more in favor of ruining the relationship rather than make any sacrifices at all. In response, relationships are becoming loveless, transactional and so flaky that any compromise is seen as oppression by the partner. There is zero self reflection and very few advises to examine one's own behavior first. It's all about oneself and the problem is always on the other side!
And unsurprisingly, these negative tendencies are bleeding into their social lives as well. Over the past decade or so, I have observed a marked increase in unsympathetic and somewhat radicalized discourse. Amateur advice is very harmful and this is definitely a massive case for the professionals to manage. But they're also products of the same system (with exceptions, of course). So I'm going to criticize even the professional and academic community in this matter. In their drive towards hyper-individualism, many seem to have forgetten that humans are social beings who won't fare well physically or emotionally without relations, relationships and society.