People who have gone through a few PlayStation 4 controllers while trying to level up their game can certainly understand the frustration of having to buy pricey Dual Shock 4 controllers on a regular basis. The controller certainly has some durability issues, and the culprit seems to lie in the build on their directional pad.
As KS Tali noticed when he cracked open his controller, he found that there were key difference in the build between the PS3 and PS4 directional pads. While the PS4 pad has small holes for the rubber contact sheet to fit into — making them more stable within the casing — there are issues with perforation around the contacts that cause them to fall apart quickly. His solution was to line up a PS4 contact sheet with a PS3 contact sheet, poke the required holes into the PS3 contact sheet, and place that into his PS4 controller — thus making his PS4 controller much more durable.
Pictures showing the differences are shown below.
Source: KS Tali (Facebook)