It's actually easy to build a Qi power receiver. A DIY one to add (ready made) is about $15 on Adafruit.
How it works:
https://www.allaboutcircuits.com/tec...less-charging/
The Wikipedia article is pretty useless.
A decent Qi Charger is harder to make.
Basically it's just an RF switching power supply with the transformer split between the charger plate and the gadget receiver. Also more limited in power than a direct connection. A Sage can charge from flat in less than 50 minutes by using about 1.5A. The add-on Qi power receivers are usually 0.5A, so x3 charging time. You need contact and reasonable alignment. As a USB-C fits in either way round and is quicker to insert I can't see the point of Qi. Of course there are Frand patents, which only possible because the USPTO is broken. The actual use is at least 60 years old and transformers with the two parts separate are maybe 150 years old, more than 120 anyway.