There are rack designs out there built on this idea, but they are usually pretty specialized. For example, the Cray XC series has racks with built in power, net

There are rack designs out there built on this idea, but they are usually pretty specialized. For example, the Cray XC series has racks with built in power, network, and out of band monitoring. A downside of this kind of thing is that it makes upgrades and maintenance harder, and you often have to do any hardware work on a whole rack at once. Heterogeneous setups get really hard. And it’s usually very vendor specific.