“Joint family system is success”…sounds like an absolute in which you’re leaving no room at all for any exceptions or cons for such a living arrangement.
Sure, joint family system has its advantages such as greater collaboration in household chores and raising children. (And there are exceptions to this as well).
Sometimes…the more people under a roof…more toes can be stepped on…more boundaries can be crossed…and more effort needs to be put forth in maintaining a healthy balance between the relationships.