What Framework is trying to do feels like something that would've made more sense 10 years ago.
And the reason for that is b/c of Moore's Law approaching its end.
The way to manufacture more efficient compute now is do things like put DRAM closer to the chip and even closer integration between CPU and GPU. The fact that Apple can co-design their silicon such that the CPU and GPU can pull from the same pooled RAM is a major advantage over competitors. There are also latency and bandwidth benefits how they setup their RAM just from pure physics. And chip manufacturing is moving towards chiplets where you have cores manufactured separately and then wired together at nanoscale level on top of a silicon interposer.
The current best-practice unfortunately is closer to Apple's "hemetically sealed appliance" philosophy, and not the "I build my own PC" philosophy.
When you have CPU, GPU, and even DRAM sitting on the same "die" the only things you're going to be swapping out on your Framework laptop are going to be relatively trivial.