I hear a lot of lamentations about the demise of the joint family system. Such people never lived in one or were surely not the daughters-in-law of a joint family.
In an average joint family, the father-in-law lays down the law and all must obey about how much money is to be spent, who is allowed what who goes where etc. On the domestic front, the mother-in-law decides who should do what work, what and how much to cook and who should be given how much food. Usually, the daughter in law gets to do all the work and has to eat last what, if any, is left over.
The situation is better if the household is wealthy, where cooks and maids do the heavy work. still, what to do, where to go when to even visit relatives is never in the daughter in law's hands.
There is a study that shows intra-family status of the mother determines the child's nutrition level.
I have experienced life in a joint family for short spells, and though it is fun to play with cousins, the work that the women do is tremendous. However, cunning women can game the system and make life easier for themselves, worse for others.
The accepted standard model is however, ill treat the daughter-in-law.
The joint family for all its ideal of binding people together, does not guarantee that a man will not physically abuse his wife. That also happens with the in-laws looking on.
 In short, joint family is good for the top dogs.