Why did agriculture begin at all, after two hundred thousand years of successful foraging?

Farming arose independently in at least seven world regions within a few thousand years of the last glacial period's end, which demands a general explanation, yet no proposed driver has won the field: end-of-ice-age climate change, population pressure, resource abundance making settlement possible, social competition and feasting, and cultural or religious change all have serious advocates, and early farmers were by skeletal evidence often worse nourished than the foragers they replaced, so the move was not an obvious improvement to those who made it.