Fatty liver can restore themselves if you stop drinking or taking medication that’s causing it, or change your diet. However, once it gets to a cirrhotic state it’s scarred and therefore can’t really recover. Most people do have fatty livers in the western world once you are Middle Aged due to diet but it’s treatable. Also liver function tests tend to show damage before the physical signs can be seen on imaging. Cirrhotic livers though can be a ticking time bomb.