Question: is gyro ball a good move?
Answer: The main reason to run Gyro Ball, is Stakataka's pitiful base 13 Speed, which lucky for it, allows it to run Gyro Ball to great success, not outspeeding literally every Pokemon in the metagame except for six: Munchlax, Shuckle, Pyukumuku, Trapinch, Bonsly, and Ferroseed.