Grounding is important for shunting the surge to ground.
Keep in mind: surge protectors and UPSes are not necessarily going to prevent damage directly caused by lightning. Lightning has a lot of energy and is high frequency and can make its own paths to ground through and around protective devices.
Lightning strikes cause power outages in a larger area. When power returns, you can get a high voltage surge. This is what surge protection suppresses and protects against.
Keep in mind: surge protectors and UPSes are not necessarily going to prevent damage directly caused by lightning. Lightning has a lot of energy and is high frequency and can make its own paths to ground through and around protective devices.
Lightning strikes cause power outages in a larger area. When power returns, you can get a high voltage surge. This is what surge protection suppresses and protects against.