> You can use a wheelchair to get everywhere, but your leg muscles will start to wither

Although it's not to the same degree of atrophy, I've been thinking of cars the same way. They're too easy to use once you have them, just press the pedal, so you stop walking and everything becomes a matter of driving distance, which makes it acceptable to distribute commercial activity in stupid little pockets of car destinations and avenues separated from each other by noise, pollution, and danger. People may not physically atrophy to the point of having no leg muscles, but their tolerance for walking a km becomes much more strained and their appreciation for investment in public transport lessens. They don't see or speak to people as much because they're always in their portable silo. You burn less calories, it's easier to gain weight, and people discount the value in having a gym within walking distance.

It's tough to reconcile it with being a functional tool, because although I could conceivably use it as one and buy one, I know that it can become an addiction.

Sure thing, sometimes it's fun! I suppose that's because I'm a thrillseeker. Let's see how fast it gets up to is a test. That wouldn't be the case if I were driving.