First, personal flying vehicles are definitely not going to be a common mode of transportation. If and when this happens, it will be for ultra rich, select few people, effectively replacing a private helicopter. We don't have the infrastructure, regulation or technology to have millions of people buzzing around in their astro-ford like the fifth element - this is still very much science fiction.
Second, scooters and bikes need infrastructure, which in 99.99% of the US, is not made for this. In fact, current infrastructure is very much hostile to bicycles and scooters, so in order for this to work, there's going to have to be a massive investment in new infrastructure all over the US. Is this very likely? I wouldn't say so.
The US locked itself into using cars through massive, expensive infrastructure and culture and I don't see this changing easily.
The population growth slowing might be true, but it's still growing, and there's still a profit to be made there.
The new factories are going to replace manufacturing in foreign countries. I'm not sure the effects on supply will be drastic. It's just a matter of building cars domestically, avoiding tariffs and securing domestic pipelines.
Finally, asking these corporations to "look 20 years ahead" instead of maximizing short term profits, is a common tradeoff that they are all aware of. Currently, short term gains is what's being preferred in almost every industry. I doubt any board members will vote to leave money on the table for long term benefits. More money now always wins.