Electric power steering is cheaper and more reliable than hydraulic power steering. It also puts a much lighter load on the engine.
It's still a rack+pinion steering rack, you don't lose all steering if the electrics go, you just lose the assistance. You can drive the car perfectly well without the power steering, just don't try any parallel parking.
A hydraulic system has a lot more moving parts (and more electronics these days!) and a much larger possibility for failures. In comparison, an electric power steering system has a couple of sensors and an electric motor centered around the steering column. As far as I know, the fault happens in the sensors. A modern hydraulic power steering system would have failed in the exact same way if the sensors failed.
And is more environment friendly, imagine hundreds of gallons daily poured down the drains etc