FedEx often losing packages - are they running a scam? Has this happened to anyone else?

FedEx has lost several high value packages in the past year and I am beginning to wonder if they have some scam going on. The high value packages are coming in sets of 3 - and the 2 lightweight cheaper ones get delivered, but somehow the more expensive, heavier one piece gets lost - maybe 3/50 packages this has happened to, which is a pretty damn high occurence rate. Does anyone have any experience like this? I am thinking of delving into this more deeply because at this point, it no longer seems like a coincidence.