As every medical student comes to learn when first dissecting the human body at medical school, our limbs are almost entirely composed of muscles.
Only an organism of our dimensions and android design — 1.5 to 2 meters in height with arms about 1 meter-long ending in manipulative tools — can handle fire.
Being terrestrial is one obvious requirement. No fully aquatic species could master fire and thus develop metallurgy.
All these elements of fitness in nature for the development of technology, crucial to mankind’s rise to civilization, long preceded man’s arrival on Earth.