Usually the siding is so ruined it will never look good, even when painted. Sub flooring and the foundation of your home may be compromised. I've seen people have to find someone to crawl under their home and replace the whole foundation. Overgrown foliage touching your house provides secret tunnels for insects to invade your home. In some areas, not spraying your foliage leads to ugly gray scales on the branches, that you can never get rid of.
Neglected lawns turn into nothing but weeds and moss.
Often they have to be totally stripped and replanted. Water Damage and Insect infestation are the biggest consequences of neglecting your home. One leads to another, as insects love wet, rotting wood. Termites and carpenter ants can destroy your home. Home ownership is a big responsibility.