If braking power is reduced, is it always caused by the brake pads?

Not necessarily. Reduced braking performance can also result from issues with the rotor or caliper, not just the pads. Some rotors are made from lower-quality materials that overheat, warp, or lose structural integrity over time. Overheated rotors may become tempered, leading to permanent loss of strength and an increased likelihood of noise. In such cases, even replacing the pads will not fully restore braking performance. We recommend inspecting rotor flatness, thickness, and color changes, as well as ensuring the caliper is functioning properly, whenever you experience performance loss or unusual noises.