[Tobba_]

Seems like most people here are bringing up speed of light problems, which are a concern, but it's not what stops you. The problem is that your yield goes down exponentially with die size, and binning them becomes a clusterfuck. The opposite direction of making smaller dies is fairly attractive though. For example, AMD split Threadripper into multiple dies on an MCM and seem to be saving a fortune on it, at the expense of some die area for interconnects. That way they can test and bin dies individually an assemble an MCM of known-good dies from the same bin.

I remember reading that GPUs are getting to fairly monsterous die sizes though - and they're paying for it.