I mean, there already exist mats with multiple charging places. What Apple aimed to do was something that also charges the Apple Watch (which doesn't support straight-up Qi IIRC), charges the AirPods, for which will be necessary for Apple to also release the wireless charging case for them, allows for some free flow placement on the mat and displays a fancy UI on the iPhone indicating the battery levels. It's not just a tall order, but it's really off-limits for 3rd parties. Last thing it was heard it even ran its own version of iOS.
Wireless charging is really counter to Apple's forward progress on environmentalism anyway. The Qi standard has 30-40% energy loss depending on the manufacturer. For one device, sure, that's not going to do damage to the environment. But Apple thinks in terms of millions of devices, and that energy waste adds up.