Bipedal locomotion has several advantages.,
1.) you can see further in steppes, which is why it's believed mankind as we know it originated from a steppes-like environment with only few trees and lots of high grass
2.) it uses less calories and it's faster than quadrupedal - we can take longer walks/runs and outrun our primate ancestors with less muscles to feed, which is why we can afford to have a huge brain
3.) it stabilizes the head - our head is far too heavy (in relation to our body) for a quadrupedal animal, which you can easily feel if you just look up while crouching, it's straining - of course with bigger neck muscles that can be compensated for, but these muscles need a point to connect to the head, which leaves less space for the brain
4.) you have your hands free
