The Punjabi rural household was traditionally joint: brothers and their families under one roof or in one compound, farming undivided land, with a common kitchen and a senior man managing it.
It worked because holdings could not be split without becoming unviable, and it broke for the same reason: inheritance divided the land anyway, and by the third generation the shares were too small to farm.
Punjab's average operational holding has fallen steadily and is now around three hectares, with a large proportion below one.
Emigration, urban work and the separation of kitchens have done the rest. The nuclear household is now the standard form in Punjab as elsewhere.
What went with the joint family was the care arrangement: elderly people, widows, the disabled and unmarried relatives were absorbed into a household that had room.
The joint family was not a sentimental arrangement and its dissolution is not a moral failure. It was an economic structure and the economics changed.
The joint household holds land undivided while the brothers work it together, and the division comes at a death or a quarrel and is then recorded in the revenue papers.
Fragmentation is the consequence. The average holding has fallen with each generation and a very large share of holdings are now below the size that supports a household.
The emigration of one brother is the standard solution: the land stays whole, the household gets remittance, and the arrangement holds until it comes to inheritance.