Can anyone tell me where the progress in audio went?

@moonwatcher, +1

Much of the progress is in profits. I would put a 1940s Shearer horn up against any of the greatest of today.

@moonwatcher ,

Perhaps with your camera analogy should be the recognition that some things you really can't improve or are as good as ever needed for human consumption. Look at pixel count. If you are not blowing it up and/or looking at a printed version close, 12 megapixels can display all the resolution our eyes are capable of picking up. You can add more pixels but you won't see any more as your eyes simply do not have the resolution.  No ones eyes have the resolution. The same is true of audio. This concept of "everything matters" has to be one of the dumbest things in audio yet I wonder how many people have typed it on these forums just this week? There are limits on what we can hear, let alone detect in music. They apply to everyone. There are minor differences but they are not all that great, and the main difference is training. This flawed idea has been used to justify all kinds of things are just nonsense and is used as a crutch by people to avoid accepting their own limitations. Just think if the spend in HiFi was redirected from all the things that make little or no difference into the things that actually do and the companies that do them?  Maybe it would make no difference, but given the op feels, and I tend to agree, that the industry is rather stagnant, change would be welcome.

@theaudioamp you wrote, "I would argue that lenses still have a long way to go, especially when price is taken into account :-) "....My nephew who has a few Sigma Art lenses would say his are "good enough" and especially his wife, who looks askance at his spending on hobbies like audio and photography... ha! 

I am a big fan of "Walking Around" lenses, you know those ones with big zoom ranges. Ken Rockwell may suggest framing with your feet, but try that over a body of water, or where access is restricted or physically impossible. Those still have a long way to go.  Inexpensive lenses still have a lot to be desired when used outside their sweet spot.   The Sigma Art stuff is nice.  One area of considerably improvement would be using plastic for internal lenses in the assembly. That would dramatically lower weight. The quality however is not there for plastics yet.