maybe so, but how many plumbers pressure test all their pipework for potential leaks before introducing water? we have to. it's called IR testing. wet-pants gets it wrong, someone gets wet. we get it wrong, someone may die.
Most do, I certainly do. Leaks cause dangerous and/or expensive problems too. Perhaps not as deadly as electricity for the most part, but I would say the potential of a well installed plumbing system to cause problem far exceeds that of a well installed electrical system. A plumber can do everything right and still get a suprise and unfortunate result.