Why did states abolish laws of primogeniture?

States abolished laws of primogeniture primarily to promote greater economic equality and land distribution among families. These laws traditionally favored the eldest son, concentrating wealth and land in a few hands, which hindered social mobility. By eliminating primogeniture, states aimed to encourage broader land ownership, stimulate economic development, and empower younger siblings, contributing to a more egalitarian society. This shift reflected changing societal values and the desire for more democratic principles in property rights.