Comment by Aurornis

That’s a laptop. It’s soldered for space constraints.

There are high speed memory module form factors. It just adds thickness, cost, expense, and they’re not widely available yet.

Most use cases need the high speed RAM attached to the GPU, though. Desktop CPUs are still on 2-channel memory and it’s fine. Server configs go to 12-channel or more, but desktop hasn’t even begun to crack the higher bandwidth because it’s not all that useful compared to spending the money on a GPU that will blow the CPU away anyway.