Nearly all manufacturers do not advertise/exhibit their product measurements? Why?

@kota1  and @coralkong  We obviously think alike.  There is a point of demarcation, especially for trained listeners, where we know what we are hearing and can over 30 days make a "sound" decision.  

I guess in the circle I run with, remastering engineers, musicians, audio equipment manufacturers and audiophile friends are too stupid and uneducated to know better than test and measure audio equipment to prove they have made the correct choice.  I don't think so.

@westcoastaudiophile My neighbor and friend did not have anyone criticize his system but he heard others and knew there was something missing.  His system had/has great ambient soundstaging, good tone color and dynamics.  Many of his recordings sounded listenable.  Others did not.  My system pointed out to him that his was missing consistency, just like my choice of a Dynavector 20X2 L cartridge, whereby all my LPs sound was elevated, or my digital system which makes so many of my mono recordings (especially jazz) sound as real as stereo.  His system was so inaccurate that when a bass was played, it had notes up and down the scale come forward and recede, a highly irregular frequency response.  Once the new power cables were installed, playing a bass was a gripping experience with no holes in the scale.  My best two friends visited him as well and the one with the Golden Ear hearing within five minutes discovered further anomalies such as a metal sculpture and an open fireplace on the sidewalls were disfiguring the sound acoustically.  We closed off the fireplace and removed the sculpture and the sound became more coherent.   My neighbor was very thankful for the help.  His other cabling is Kubala Sosna and high end Siltech which sounds just fine in his system.

@fleschler thanks for your “story”, your “sales" skills are outstanding!

on other hand I am still not getting answer on my question, what manufacturer’s measurement of original cable is missing, and what measurement “improved” cable exceeds on?

One of those best friends had worked part time a decade+ ago for a major audio high end retailer. He brought home a lot of equipment. He was generally dissatisfied. It is when he met my best friend (Golden Ear and remastering engineer) that he settled on his equipment which consists of a VPI Scout+/arm, Dynavector 20X2 H, McIntosh C20 (2nd version), RAM RM 9, Kyocera 310x and Von Schweikert VR35 export. He was still unhappy with his sound (this is in 2020). I proceeded to suggest changes which he gladly did. These included giving him a Black Synergistic Research power outlet, removing the cheater plug on his amp, replacing the XLO cable with GroverHuffman Empress cabling from 2016 for the CD player, pre-amp to amp and very low capacitance, all silver turntable cabling. He had a good quality turntable power cable and the other equipment have captive power cables. His shelves were wood and set on screw points on his stand. Two wobbled where the pre-amp and CD player stood. He replaced the screws and stuck blu-tack instead (his VPI sat on Aurios and a 2" thick concrete slab).

The result of my and his tinkering with cables, shelving and tweaks was utterly amazing. He is ecstatic with his system and although it is not high-end, it is oh so beautiful to listen to. His speakers permit great imaging and soundstaging nearly 90 degrees seated on side couches. He has excellent deep bass and full dynamic sound. Total current cost of his system is under $15K. (The VR35 export are superior to the VR33, using parts quality from the high end speaker line). He has returned the favor by introducing me to be-bop/post-bop jazz (he has the very expensive LPs) on CDs. My 50s-70s jazz collection has doubled by about 300+ in the past year (I have a sizable early jazz collection as well). Great performances and great sound. He purchased a large collection (55) of Mercury Living Presence classical CDs from hearing my complete collection.

This is where the enjoyment comes in and not in measuring equipment for my friends and myself. Give us some measurements so that we understand the limits and interactions of equipment, then listen for the rest. Cables and tweaks to date, require listening only without adequate (easy and quick) testing.

@westcoastaudiophile I don't know of any high end/expensive/boutique cable manufacturers who provide testing measurements of their cables.  I certainly don't know how the better sounding cables measure.  Similar to my prior occupation as a commercial real estate appraiser (not to be confused with residential appraisers), my exhaustive work involved both science (math, computer models, physical inspections, details, interviews) and art (interpretation of non-physical elements such as location, effects of details on the adjustments such as environmental issues, etc).  I provided reasons for all my adjustments, based on paired sales analysis and judgment calls (based on my experience and interviews).  

So it apparently is with cable manufacturing, a mixture of science and art.   I can't explain it.   I would hope that manufacturers would do a better job of it rather than puffery.  While most explain part of their cable construction, many don't, possibly due to proprietary construction limitations.   Even some of the most expensive cables have virtually no information (MasterBuilt, sound great in systems I've heard but I have no idea why).  

@fleschler +1, the most important measurement= listening satisfaction :)
In LEAN manufacturing they have a saying, what gets measured gets done. The problem is you can measure too much and get lost in the details. This is why I stick with the 80/20 rule. 20% of any system provides 80% of the results. I don't see the value of buying a DAC or a cable that measures so well that only a bat can hear the difference. If you get that 20% right the rest is an adventure toward a moving target which we can only aim at but never hit...perfection.