The library.json file has not been maintained. The version is outdated and it also has an incorrect platforms value. So the evidence makes it obvious that having two metadata files in this project has a harmful effect. Since the Arduino development software requires library.properties, the choice of keeping library.properties and removing library.json is clear.
library.json is PlatformIO's native library manifest file but library.properties is also supported: https://docs.platformio.org/en/latest/librarymanager/creating.html
The library.json file has not been maintained. The version is outdated and it also has an incorrect
platformsvalue. So the evidence makes it obvious that having two metadata files in this project has a harmful effect. Since the Arduino development software requires library.properties, the choice of keeping library.properties and removing library.json is clear.Supersedes https://github.com/arduino-libraries/NTPClient/pull/78