Third party apps generally do not provide as accurate information about battery health. The algorithm they use, is not as accurate.
Batteries, like people are individuals. No two people age exactly the same and batteries don’t age the same either. The exact usage, chemical makeup, storage conditions, exposure to heat and cold and about a dozen other factors mean that every battery ages differently. Battery aging is not a linear (straight line) and degrades at different rates as the chemicals in the battery age and other factors mentioned above. Apple expects your battery health to be at 80% after 24 months. If your battery health misses that expectation, contact Apple Support.
Please review the Apple Support articles on battery optimization. It contains the best current practices for battery charging.
iPhone Battery and Performance - Apple Support
Batteries - Maximizing Performance - Apple
About the battery and performance of iPhone 11 and later - Apple Support