If your car has been parked up for 12 months outside then I would argue that the annual service is more important than ever before. The tyres may have suffered UV damage and started to crack/perish, the brake fluid could have become contaminated by moisture or there may be a fluid leak that needs addressing. Cars are not designed to be left standing for long periods. I would consider the service a must, especially if you plan to start driving longer distances in 2021/22.