Rooting voids your warranty and, if done incorrectly, can "brick" your device. However, for an older device on Android 4.4.2, the benefits usually outweigh the risks, especially since most of these devices are long out of warranty.
This is often caused by Google Play Protect. Since Android 4.4.2 is no longer updated, you may need to disable Play Protect in the Play Store settings to allow the exploit to run. Download Iroot Apk For Android 4.4.2
Since iRoot is not on Google Play, you must enable installation from unknown sources: Rooting voids your warranty and, if done incorrectly,