It comes down to the cost of solar panels. In the last few years, we have seen solar panel prices drop by more than half. This price drop has made peak clipping an advantageous strategy. It now makes more sense to install additional solar panels, rather than add other older and more expensive solar efficiency technologies (like sun-tracking and tilt variation).
The solar power inverters limit the size of the array, so putting more solar panels on is better for production. As higher wattage inverters and solar panels are used, fewer of them are needed to generate the same amount of power. That brings the overall price of a solar installation down.