Eight speakers versus twelve doesn't have comparison because the hearing system perceives multidirectionally in nature. This cannot be emulated by headphones if you account that sound creates perceptions beyond the ear. Vibration, presence to name two of main relevance.
To mix twelve speakers means one track per unit and nothing in comparison with the ease —well, relative other time— of a stereo pair and independent amplifiers for each unit thus the power consumption obviously increases as a multiplication factor. Conventional speakers do a very bad job in terms of energy optimization as we should remind.
What is also unforgettable seems how any person could instantaneously locate a sound source in any omnidirectional field. A-B tests with 5.1 versus 11.1 perhaps it's better not even say it or why not 55.5! It would appear a moment where another speaker must be classified as redundant and no one would note when it's working or not.
Perhaps this tree could be another with a different technology, with a single amplifier and installation with the ability of placing sounds in say a dome or a convex surface. Digital lines, multiplexing and that, a format that allows the user to say, "this one at these coordinates". If it goes to 22.1 some users would not install it in their homes!