Routine excessive battery temperatures affects the performance of the phone as well as the health of the battery. The battery is an ever-changing chemical reaction. It's performance is not linear. As such, long term use of wireless charging, especially a charger that is cheap and not very efficient with its coils can produce a lot of excess heat which in turn raises the temperature of the battery and phone casing. Order time, this kind of usage can cause the battery life to degrade faster than it otherwise would with wired charging. Each phone battery is different. One person may have a battery that last a lot longer than another person due to usage type, apps use, and as noted, environmental usage of the phone. It is best to not subject the phone to excessive cold, heat, or excess drain on a regular basis.
The best thing to do in my opinion, is make use of the optimized battery setting in iOS 26, and use your phone as you normally would (and with common sense usage). And if the battery gets under 80% after before a year, Apple will replace for free. Should that happen after a year and you still like the phone, pay for a battery replacement. Don't obsess of the battery. A lot of people here do just that and that isn't good.
