In the pistol world, a lanyard is typically long and connected to the belt, to retain your pistol in case of a drop or someone grabbing it. This is not the case with blades.

A simple lanyard is more of a loop. It helps you pull the blade if found in a cover (pocket, pack, etc), it helps your hand orientate to proper position (like a muscle memory action, having a common ridge to guide from... this helps people draw. Lastly, a simple loop will keep your hand from ever sliding forward over the blade. It changes all 'work' to not only finger/grip strength, but also wrist strength.

The more elaborate designs are often to put more 550 test para cord on your tool, should you ever need it, you can unravel it and use it.

Lastly, like on a Chinese spear, a wooshoo type distraction to complicate what the eye (of the non user) sees.

For me, a simple loop is always on my users... but just two days ago I began putting D-Guards of a few blades, and I love it.. tighter retention accross the board.