Drop weights were in favor for Cave divers back in the days before buoyancy compensators were common. So the weight used to descend became a liability when you wanted to swim at depth and maintain good control with your compressed wet suit. With a good BC, wing, or drysuit it simply is not an issue any more.
That pretty much covers it.
With regard to potential over weighting and a wing failure, I dive a dry suit to address that possibility. With a dry suit in cold water with suitable undergarments, I am near neutral with near empty doubles with a 6 lb SS plate. I tend to dive the same plate in warmer water caves requiring lighter undergarments. I have a 2 lb AL plate that would technically be better in terms of ideal weighting, but I'd rather be a couple pounds heavy than a couple pounds light, especially if I want to loft the insulation a bit more than usual on a long deco stop after a long dive.
I could argue that I do use a "drop weight" from time to time, but it will have about 45 cu ft of O2 in it, so it still serves a purpose other than just weight. It is not, in any event, needed to correct a too buoyant condition at the end of the dive.
A diver needs to approach the whole weight issue as an integrated system. For example, the diver needs to know the bouyancy traits of the basic harness, plate, wing, tanks, can light, backup lights and suit, then consider the impact of items such as full and empty stages, deco bottles, etc to ensure you have enough lift at depth to stay neutral and enough weight to hold a 10' deco stop with near empty stages and near empty back gas.
When you consider the buoyancy traits of steel doubles, a plate, can light, backup lights, reels, etc, it is obvious that drop weights are probably not going to be needed as you are already going to have more than enough weight.