Our means of travel have also gotten vastly more efficient.
Prioritizing progress in average efficiency over speed of a showpiece that is used for a very small share of actual travel isn't the end of progress, and it is very much change in the world of atoms, not bits.
Hardly vastly. At best within an order of magnitude better, but not even close to that.
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...
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.
For efficiency to be considered a huge leap in progress, it needs to be a change on the order of magnitudes....