A lot of people are missing the point. Soldering means stocking and holding multiple boards with multiple different combinations of CPU/RAM/GPU in inventory.
By making it socketed, you only need 1 boards and then just insert the different parts as needed. You don’t need to stock much and instead you can easily make to order. LPCAMM2 memory, can, for example, be installed by a machine at a factory, so if user 1 and user 2 order a 32gb and a 64gb laptop, the laptop construction can happen quickly and without resorting to having tons of inventory.
Inventory is real estate.
Most companies use lean manufacturing and avoid holding inventory wherever possible. Some additional info on this:
https://en.m.wikipedia.org/wiki/Lean_manufacturing
Also it does relate to APUs because it is very likely LPCAMM2 is rolling out soon, if it hasn’t already.