My guess is just that Bluetooth and Wi-Fi came first, and when wireless USB entered the party, there wasn't a real need for it, as most of its use cases were already covered by Bluetooth and Wi-Fi.

It maybe could have worked with better marketing, but convincing potential customers to change something that works (somewhat, BT wasn't without issues) is hard. That's why we are keeping abominations like cigarette lighter sockets in cars even though they often can't even light cigarettes anymore. It is already well established and it works well enough as a power outlet.