The difference is, the Wright Brothers started with a _very_ fundamental understanding of the physics of flight, developing an understanding as they go, while internal combustion engines and electrical motors are very well understood --- the big question is what will be the breakthroughs in battery chemistry and physics and other energy storage systems --- and what the constituents of the earth's crust will allow us to build in quantity.

We've already had one company get caught out by picking a battery chemistry before securing an adequate supply of the rare earths which it needs.

For life, either potassium or phosphorous is the limiting element in the earth's crust --- which element will be the limit on what electronic gadgets we can have?