Both systems are a fraction of the size of an ATX case and as efficient as they needed to be to meet their predetermined convective cooling needs. In both case

Both systems are a fraction of the size of an ATX case and as efficient as they needed to be to meet their predetermined convective cooling needs. In both cases, profit margin is increased by reducing material and shipping volume requirements. A similar single heatsink design for high end PCs would need to be much larger than either of those designs but considering how much empty space is in an ATX case, I don't think it would be much larger than current PCs. Consider that the best PC cooling solutions all look like this: https://assets1.ignimgs.com/2018/01/18/cpucooler-1280-1496174542219-1516305067126.jpg https://assets1.ignimgs.com/2018/01/18/cpucooler-1280-149617... Or pass liquid through a radiator with comparable volume, standardizing the contact points for a single block heatsink with larger fans would make computers more efficient and quiet.