Wireless Charger or USB-C on a new iphone 16 pro max

You should be able to use either method if you are using an authentic Apple charging device.

Although wireless charging does tend to produce more heat during charging and you should take that into consideration if you charge your phone in a hot environment ... like inside your car.

Either one is fine. Apple’s charging options are optimized to produce the best battery life possible. Don't pay any attention to the misinformation spread about by those of questionable knowledge about how to charge, when to charge, how far to charge, etc. It’s all blathering nonsense. Charge your iPhone 16 Pro Max as you see fit. Don’t get all caught up in the battery arguments. Batteries begin to degrade the second they are put into service.

I followed my own advice with my iPhone 13 and when I traded it on for my iPhone 16 Pro its battery health was still around 90% after years of use.

As long as both the wall charger and wireless charger (qi2 wireless charger for iPhone 16) are made of high efficiency, your battery will not be impacted. Using poor quality chargers can impact battery health.