The U.S. is Apple’s largest market and, like other countries, chargers are excluded here as well. The problem with using pricing and price changes in other countries is that those may be due to currency fluctuations which skews things.
The U.S. is not the one market where prices haven’t been hiked. We can also look at prices in Brazil e.g., the starting price of the iPhone 13 in Brazil was $7,599 BRL (less with cash discount) and the starting price of the iPhone 14 in Brazil is $7,599 BRL (less with cash discount).
A reason prices like these have been more stable is because the U.S./Brazil exchange rate when new iPhones went on sale in Brazil has been more stable than other countries. Again, exchange rates are largely to blame for increasing prices in some overseas markets and therefore not necessarily a good basis to gauge Apple's pricing activity.