Framework isn’t using LPDDR5/5X like the surface or the macbook. LPDDR adds to the cost quite a bit, as does the advanced packaging apple uses etc.
But it’s the only way to keep pushing bandwidth forward, especially for graphics/iGPU, and keep pushing power down. Socketed memory inherently is much slower and less efficient, same reason consoles don’t come with ram sticks.
AMD’s solution is a package with cache instead, to try and reduce the amount of data they have to push around. But that adds a bunch of cost and still isn’t as efficient - but it lets you keep scaling socketed memory a little farther. Can’t help but feel like the days are numbered though, there isn’t an infinite amount of runway left for socketed memory.
