That is the most common in datacenters, but there are other configurations. 3-phase power is becoming common. Some others. Twistlocks are also used a lot in Th

That is the most common in datacenters, but there are other configurations. 3-phase power is becoming common. Some others. Twistlocks are also used a lot in Theater lighting, and movie/tv production. Also, some generators. But yes, in general, not so common for residential, and only certain commercial tasks.