Of course it would still need power cords, about 6 of them.
The "standard" 5.1 systems are still far more popular because it's usually easier to run smaller, low-voltage speaker wire than it is to have power receptacles where you need them or drape higher-voltage extension cords around.
What many do is use a regular AVR, common subwoofer, traditional passive speakers for the main front left, right and center speakers and use a remote powered amp for the surround speakers. This is often the lower cost solution, with the added benefit of being more powerful and sounding better.
What is the room situation and limitations that make you want this "wireless" solution?
KEF R500, R200C, R100, R50, SVS SB2000 sub, NAD T758v3 AVR, LG UP875 4K BlueRay, Samsung UN55JU6500F 4K LED TV, KEF M500 headphones, Sony CDP-CE500 CD changer. Office: NAD M10, KEF LS50, KEF Kube 10b, Pro-Ject RPM1 TT w/ Ortofon 2M Red. Guest room: Hafler 300 L-R, KEF Reference Model 100 center, KEF iQ10 surrounds, modded M&K V-90 sub, Bluesound Vault 2.