People joke about this all the time, and I here the sarcasm in your comment, but technology has come far since the iphone 6 or 7.
Most high end phones have wireless charging build it. Between the receiver coil and the rest of the phone is a thin sheet of ferrite material to prevent the electromagnetic field from getting to the sensitive electronics. Battery technology has also improved a lot, so much that even relatively cheap phones like the Realme GT Neo 5 charge at 150W!
From the technical perspective the limit is the cable and connector, because there would be too much losses that heat up the cable to dangerous levels and rapidly degrade the contact area in the connectors. Manufacturers don’t want to deal with this security risk, not the increased RMA rates within the mandated guarantee period, so they artificially limit the charging rate.
Thing is: You absolutely can charge at higher speeds if you bypass the cable altogether! A microwave outputs usually somewhere between 150W-1000W, so stick to the lower end to be on the safe side. The screen of the phone must face down, because the charging coil is placed on the back. You also must prevent overcharging by setting the timer correctly: If your phone battery has 15Wh capacity, and you are charging with 150W, you must at most charge for 1/10 of an hour, or 6 minutes (less if you are just topping up your phone).
One final note: fast charging does put increased wear on the battery, so I only recommend to use it when you need it, for example when you need to make a flight and are already running late.
A slight heating is perfectly normal and nothing to worry about. A microwave is fine tuned to heat food, or more precisely the water within. Other materials such as the glass on the back of the phone also absorb some energy, but only a tiny fraction.