Subaru Crash testing is performed with new cars made solely of genuine parts. Modern cars are complex systems. Changing one part, even parts that seem like that may make no difference to crash performance, can change the way that system protects vehicle occupants and other road users. Changing one part can change everything when microseconds count.
You do not want to chance that the new brake pads you fitted recently will work. You need to be sure they will because the alternative can be a complete disaster. When you insist on genuine parts, you can be sure that the car will work as originally intended. They will work within the specified mileage, saving money and giving you peace of mind.
Subaru cars are renowned for reliability. That does not hold where maintenance is carried out using non genuine items.