According to Locke, why do people choose to enter into a society?

In chapter 9, Locke revisits many of the discussions of previous chapters . He begins by asking rhetorically why any man would willingly leave the state of nature, a state where he is completely free and equal, to be governed by an authority. This is because the other men in a society still in a state of nature cannot be supposed to respect all men’s freedom. A man’s property may be invaded, his life may be threatened, and other men’s self-interest may preclude their acting for the common good. Life in a state of nature can be dangerous and full of vicissitudes. This makes it necessary for men to want to form a government to preserve their lives, liberties, and estates (which Locke reminds his readers all constitute the term “property”).

why would man want to join others and enter a society when he is his own master over his property and possessions?