>>96162801
Mine has two reasons for the rise of mecha over conventional weapon platforms
1: The Mind Machine Interface. When you allow a person to control their machine at the speed of thought, it is easier to train someone to control a mostly humanoid body instead of a tank or a helicopter. So what if the body is thirty feet tall?
2: It is easier to bind the spirit of mythological creatures if the vessel resembles them, same with the spirit of heroes.