They are easier on parts, and they don't have belts like blowers, or turn into cutting torches like nitrous. A turbo LS with mild camshaft and stock rocker gear can make 1000hp, same with a gen III hemi. You can make a lot of power with a mild engine.

One year on drag week there was a guy who won the sealed hood award and it was a turbo corvette than ran low 8s or high 7s. I don't think you could do that with any other power adder.