It's remarkably difficult to maintain signal integrity/etc if it's not very close to the CPU at the signal rates they are getting to. This is already a serious

It's remarkably difficult to maintain signal integrity/etc if it's not very close to the CPU at the signal rates they are getting to. This is already a serious problem. For places where you are willing to give up power efficiency, or latency, or both, this is not as big a deal - this is why you see CXL/etc. But for a laptop, where people want power efficiency, latency, etc, this is a serious issue.