Why no high end battery powered wireless speaker systems?

I would love to have a set of wireless battery powered high end speakers and subwoofers.  With so many high end powered speakers  and subwoofers around these days, it would seem to be the logical next step to make them battery powered and eliminate all the cables.  I'm a little surprised that Sonos hasn't created a wireless system yet with their Play 5 speakers -even though I don't think they have any interest in cultivating the audiophile market. What are the hurdles standing in the way of this?  Are there any in the works?