If growing diamonds is the thermal bottleneck of manufacturing processes, one could imagine a sci-fi future where rather than silicon wafers serving as base mat

If growing diamonds is the thermal bottleneck of manufacturing processes, one could imagine a sci-fi future where rather than silicon wafers serving as base matrix material to grow ancillary structures upon, it would instead be diamond wafers that are used to subtractively etch structural scaffoldings, around which silicon-based structures are grown, the diamond scaffolding serving simultaneously as bone and blood vessels for thermal and power conduction as well as mechanical support.