Why men are hellbent on living with their parents

So I belong to a college group where many women post their marriage story as anonymous. I have seen a trend most married women are in troubled marriages because of their in laws, where they are living with their in laws and expecting her to do household chores and do every traditional role and making her life hell (not just about household chores but also manipulation, lies, not giving her good treatment etc) And when she leaves their home, then obviously next step is divorce or separation. In this situation, the husband doesn’t take stand for his wife or don’t do anything.

Now I have a question, yes I get it there are elderly parents and men supposed to take care of them but if in laws are making your partner’s life hell why not live separately and live peacefully?? Also I don’t understand many guys before marriage live alone but after marriage their first condition is to live with their parents, I mean why ?