Full swings have momentum to spare. Partial shots don't.
Wedge play exposes instability that full swings can hide. Yet most golfers buy wedges off the rack, judge them on full swings, then expect them to execute delicate shots from unforgiving lies — without the benefit of the mass or momentum they need to resist redirection, slowing, and twisting.
When swing speeds drops, you need more mass. More mass means a clubhead you can feel. It means a heavier strike from a shorter takeaway. Quieter hands and less interference. A more consistent short game.