Crazy.
I remember when we went to the UM84 holster that was issued with the M9 pistols (and later in bulk for M1911 units) and how much of an improvement it was over the old leather M1916 holsters. For a country so proud of its pistol heritage, I’ll never understand why holster development seemed to just STOP for 70+ years.
I was always reasonably fond of the earlier M1912 cavalry version, which dropped from a swivel loop and allowed the holster to move with the leg. There was even a thin leather tiedown strap to attach it to the leg, far more secure than the leather thong/bootlace tiedown of the M1916.
But then as a tank crewdog, I made the acquaintance of the M3 shoulder rig, and that was that. Easy to add a mag pouch if needed, could be worn either over or beneath a field jacket, and there was a positive safety strap retaining the pistol...which could be snapped under the pistol's grip if it might be needed in a real hurry. The little snap that secured the holster to the trouser or pistol belt was slightly improved on the later M7 holster, but I've always preferred the simplicity of the M3s single over-the-shoulder strap. Simple. Effective. And best of all, comfortable when worn for extended periods, whether standing, sitting/driving, or squinting through the gunner's sight or rangefinder. On the way!