its not that simple. high performamce parts are high performamce because the devices that need the fastest speeds have the shortest traces from CPU to said device. its for instance, why the ram slots, and the fastest m.2/slot as well as pci-e lanes are nearest to the cpu, else youd have to resort to adding a south bridge.
the pi compute module works that way because the ram is already on board making it not a problem, and latency to whatever it gets mounted on isnt of highest priority for performance.
its why sodimm for instance has hit a peak speed limit, while lpdde hasnt, and why dell pitched the camm form factor for ram. distance of components to the cpu and its stability is cruicial for performance.