Regulatory requirements around insurance for cars, for example, are likely to be higher and more expensive now than they were decades ago. Therefore, someone young is unlikely to go a used car lot and pick one up and tinker.
Likewise, access to uncontaminated nature in large population centres is harder than it was when rural populations outnumbered the people living in urban environments.
Bikes, on the other hand, are great for tinkering and also small enough to be compatible with modern living. These, however, might not be accessible for someone with a low level of fitness and willpower to attain that fitness.