It has gotten twice as cheap (if you look at average ticket prices adjusted to inflation) from 70 to now. Also point about concorde - it's more fuel efficient to fly slower (look at drag coefficient [1])

So from point of view of affordability and mobility for general public - it's good progress.

[1] https://en.wikipedia.org/wiki/Supersonic_transport#/media/Fi...

>It has gotten twice as cheap (if you look at average ticket prices adjusted to inflation) from 70 to now.

Which is consistent with the gp's point that progress has slowed down.

It had gotten 100 to 1000 times cheaper, faster, more efficient to e.g. travel intercontinentally between the 1900 to 1970 that it has between 1970 to now.

Efficiency is something you begin to care about when the original technology itself is no longer providing the wow factor it used to bring.

For efficiency to be considered a huge leap in progress, it needs to be a change on the order of magnitudes....