Your battery health is fine and is undergoing normal usage. iPhone batteries, like all rechargeable batteries, are consumable components that become less effective as they age. You should change out the battery once your Battery Health reaches below 80% which will take over 2 years to reach under normal usage. Until then enjoy your iPhone.
Here is some more reading on an iPhone battery and its performance ➡️ iPhone Battery and Performance - Apple Support
Your iPhone 14 will get warm as it charges. It may even get hot at times depending on ambient conditions and the level of charge applied. All this is normal. If your iPhone gets too hot to operate then it will shut down as a safety precaution. If it has not shut down then it is not overheating and operating / charging normally.
If your iPhone 14 gets too hot to touch then you can have it examined at the Apple Store or at an Authorized Service Center and take advantage of the 1YR Limited Warranty from Apple.
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