Today's tires are better than ever before, but even with the advances of modern technology, the basic trade-off between traction and treadwear still exists. Here at Tire Rack we get to test tires at both ends of the spectrum, from 100,000 mile-rated tires (Hankook Optimo H727) to tires that can pull over 1-G on our skidpad. Take a look at "Clash of the Titans: Testing Two New Max Performance Summer Heavy Hitters" for results. These impressive benchmarks are the furthest extremes of traction and treadwear available for passenger tires.
One major question when trading away traction to get longer treadwear is whether it compromises safety. The answer is, it depends. Driving within the limits of your vehicle, tires and driving skill set is safe. Exceeding any of those limits is dangerous.
So for one driver, with a performance vehicle and a high level of ability, choosing a tire with long life but grip that does not match his or her vehicle's handling and driving style could be dangerous. For another driver, the exceptional grip of a performance tire may lead him or her to drive beyond their limits, leading to unnecessary danger.
All else being equal, I prefer to have more grip available, so I tend to sacrifice tread life to get the best traction, but there is no single correct answer. For most drivers, as with so many things, the answer usually lies somewhere between the extremes.