They all suffered from severe hardware issues that got never fixed.

Chromebook Pixel 2013 had that atrocious function key row that didn't align with the rest of the keyboard and where made of different material and had terrible travel. The Pixelbook had some terrible PWDM issues with the display and iirc it also had severe ghosting issues. Not to forget the cut in performance of these mobile fanless Intel chips because of Meltdown & Spectre. I think the Pixelbook's WiFi/Bluetooth module made by Intel also suffered from hardware faults where using Bluetooth could degrade WiFi performance and vice versa.