Structured endurance training might increase downgradings!

The climbing difficulty grading system is based on comparison. One slabby 8a on granite is supposed to be equally hard for the community as an 8a limestone roof. If the 40 meters 9a endurance challenges in Santa Linya feels much easier compared to the 10 meter Action Directe in Frankenjura, the comparison grading system has failed. During the last three years, only Alex Megos has done Action Directe 9a although possible 250 other 9a, mainly endurance ascents, have been done. One possible explanation for this is that the structured training have increased only the endurance capacity of the climbers. Today, the community might think that Ben Moon's Hubble 8c+ from 1990, with possible just one repeat the last years, is at least as hard as the long modern 9a's? Possibly, the explanation for the failure of the comparison grading system has to do with greatly improved endurance training on rock and gyms and it's structured methods, at the same time as, Huber and Güllich's power training 1990 has not been improved? Possibly, in order to do such few painful moves, the power has to be practiced on the very route as the smother indoor holds, just do not make your fingers prepared for the pain and ligament challenge?