I’m not an expert with this issue, however, from my observation I would assume many marriages have issues but are still tolerable so they survive; and there are many that are almost on the verge of breaking.
I would divide shalom bayis issues into two categories:
1. Everything is running normal w/o any outside factors to aggravate it, but spouses just can’t get along with each other. 2. Outside factors like financial stress are aggravating the marriage and causing strain in their relationship.
The former, i would assume is being caused by one spouse being ‘dominant’ type, and too controlling of the other spouse. Either other spouse can tolerate it, or he/she becomes too miserable to be able to handle it and marriage becomes destroyed.
The latter, is obviousy caused by husband feeling inferior and insecure over his failure to bring parnassah to the home; whereas he starts to feel threatened by his wife [as if she’s confronting him over is failures] and then, as a result, he takes it out on her and emotionally abuses her thereby aggravating or destroying the marriage.
I’m not a professional; this is just a layman’s opinion.