I do agree with you on the drug usage part, that could lead us to a different route altogether.. and of course no one can guarantee about the future! for instance a nuclear war and we all are doomed, few of us alive might be living underground and we might end up in a complete different scene half stone age half modern! It's just a prediction if things go right this is where we might end up.......
Regarding the flying cars stuff, buddy we might be dead slow but still on track..... watch this out, it might be of interest to you.