Gallberryjoe,
You can still wear a lanyard with them(holster), I do, my wife does not. I still keep my lanyard on my call and around my neck even when using the holster so I don't ever lay it down and forget it somewhere.
The holster serves several purposes and they wear around your torso comfortably under your arm kinda like a concealed pistol holster. Keeps the call from bouncing and clanking around your neck and chest, keeps the call safe from snags and potential breakage, and keeps the call dry and clean. To each their own.