> Boeing never build a larger passenger airplane

1. there wasn't demand for one - airliner designs are driven by the customers

2. the airport terminals would have to be rebuilt

3. the runways would have to be redone to support the weight

> why the Concorde is no longer flying

It lost prodigious amounts of money on every flight. The Concorde was a prestige project, not a practical one.

> Why did the progression from the Wright brothers to the 747 not continue for the next fifty years?

The 747 is far more technologically primitive than today's airliners. Take a good close look at the wing shape of the two, for starters.