From my understanding, there are numerous ways to get the same effect, but this is already made and comes in a bottle. Many people don't know the other techniques nor have the tools (wet pallet). This is easy mode.
If you are someone who knows how to paint and enjoys painting, this is not for you. This is meant for people who don't want to spend much time on painting. Prime it and then one coat of contrast paint and you are done. Not amazing, but not bad.
I know plenty of people that have piles of minis unpainted. This will help a lot. This is actually getting me to paint my minis as I don't want to paint 5 layers if white and 3 layers of grey.