etype once bubbled...
So my local IANTD shops asked me if i would master some instruction dive charters for eanx diver courses. I enjoy diving so i said sure. What an eye opener....almost every other dive we had someone narcing out...one dive was spectacular. We had a diver who was earlier trained in the US naval reserves (and apparently lost their edge ) narc out and do a spectacular backflip (about 50 meters sw) off a radar deck of a sunken artificial reef and almost dissapear forever, but it was a beautiful sight, we found them before they dropped the reg. This person already had eanx and was doing advanced. The person mentioned was learjetted at 2000 ft to the nearest hyperbaric chamber, it was a very,very close call.
Agree in general about fitness, though the commercial medicals are possible not that relevant, more an emphasis on aerobic/cardiovascular fitness. I live in an area where commerical divers far out-number sport divers, and the two sets of skill-bases are markedly different , and definitely not interchangable.
I think you are confusing the concepts of 'technical' diving with 'deep' diving on air/nitrox. A 50m dive on nitrox, presumably aroun the 25% mark, isn't technical. Narcosis has no place in the technical diving world, so therefore neither does the ability to task load at 50m.
If you look around the gas divers in any given area, you find the numbers actually diving is far smaller than the number claiming to be diving, and it tends to become self selecting teams anyway.