I don't think locking up the brakes has had much to do with flat spotting as has the new tyre regulations.
I don't consider traction control as a driver aid, as in many ways, it complicates the driver's job more. The drivers have to no manually change traction control settings, override the TC system and most importantly, they have to this with impeccable timing and precision - most often approaching or mid-corner.
As for power steering, I guess it is. And if we are going into the detail, the biggest "driver aid" would have to be the process of changing gears. They just flick the paddle and the car's software and hydraulics do the rest. However, in light of all the other shit they have to do (brake bias, diff pressure, lock, etc.), the whole process is extremely difficult. Let's face it, they can all drive any car incredibly quick, but it's the ability to use the technology and resources given to them to maximise their speed which separates the good from the best - and this is why Schumacher has excelled over the years. But now that the car isn't up to scratch, he is finding it quite difficult.