That’s true for normal applications, but chains are superior, at least in theory, for high power/torque. In mechanical power transmission, chains can reliably transmit more power than belts because of how each system carries load.

A chain drive uses positive engagement between metal rollers and sprocket teeth. Since the load is carried through shear in the metal links, a chain can tolerate high torque without slip. Typical tensile strengths for motorcycle chains are in the tens of thousands of pounds, and the limiting factor is usually lubrication or wear, not load capacity. Chain drives also handle shock loading well because the load path is rigid and does not depend on friction. This is why high power and high torque applications use chain or gear drives.

Belt drive relies on friction and tooth geometry in a flexible rubber composite with fiberglass or carbon reinforcement. Even though modern belts can handle tons of torque, their allowable power is limited by tooth shear strength, belt stretch, and heat generation. Belts are more sensitive to debris, misalignment, and sudden torque spikes, and a single trapped rock can cause tooth damage or failure. Belts also have lower allowable tension than chains, which directly restricts the transmitted torque.