I think that what “ruined a lot of perfectly good relationships” was NOT marriage, but our CULTURE, and its lack of support for marriage!
Yes, our culture is actively promoting behaviors and dysfunctions to destroy the morality of our young. They model dysfunction 24/7 and promote deviant, destructive behaviors. Selfish, narcissism and irrational worship of mother earth. and Odin.
The schools also destroy knowledge and wisdom and indoctrinate into “lifestyles” devoid of knowledge and reason and morality. In fact, curricula was deliberately designed (strands) to target and destroy moral beliefs—esp. Christianity. (BK Eakman).
Without virtue—you can have no flourishing long term relationships. It will never happen.
Exactly what support for marriage do you want the culture to give?