The early universe did not collapse into a black hole due to the rapid expansion during inflation, which created a uniform spacetime that prevented gravitational collapse. The big bang was not a localized event but occurred everywhere simultaneously, leading to a uniform energy density that did not generate a significant gravitational field. As a result, the conditions were not conducive to forming a black hole, as the gravitational forces were effectively neutralized across the expanding universe. The discussion also highlights the importance of understanding concepts like tidal forces and symmetry in cosmology. Overall, the expansion of the universe from a hot, dense state into a cooler phase is key to understanding why a black hole did not form.