In datacenters, you're mostly limited by the power (and thus cooling). Most commercial DCs only let you use up to about 10kW per rack. For standard 40U racks it's just 250W/RU, give or take.
There are niche expensive datacenters with higher power density, but as it stands, exotic multi-kW hardware at scale makes sense if you either save a ton on per-node licensing, or you need extreme bandwidth and/or low latency.
There are niche expensive datacenters with higher power density, but as it stands, exotic multi-kW hardware at scale makes sense if you either save a ton on per-node licensing, or you need extreme bandwidth and/or low latency.