With an optimum design, bipedal robots are likely more power efficient. Read up on the efficiency of the human gait to understand why.
In practice though, it’s really challenging to get an optimum design (the current state of the art is not even close), so polypeds are better from a practicality standpoint.
Subspace (now known as Continuum) circa 1998 via 56k modem - mine repping a 2k+ bounty 5-person turret in Chaos Zone West
Such adrenaline and joy 😂