You only need to feed an ATV when you ride it. Being inanimate, they don't have attitudes or psychologic problems to deal with. ATVs don't run away when frightened, angry, or hungry for something they smell in the next valley. ATVs don't kick when the switch is turned off.
Parts for older vehicles can be a problem. Different types of ATVs have different strengths and weaknesses (Argos float, all others don't, tracked rigs shine in snow, but are slower and can throw a track in more solid terrain, etc). Your rig dictates the geography you can navigate (interior Alaska is riverboat territory, but you're limited to the rivers and not much beyond).
In the end, your rig needs to match your mission and area of operations. Even helicopters have limitations, especially legal.