Apache Cordova is a relatively old project. As such, we deprecated serveral of our components and ceased supporting and developing them over the years. (Read more about the process behind this in cordova-contribute / Deprecation and Archiving.)
cordova-plugin-compat has been integrated into the cordova-android 6.3.0 release. The plugin should be removed from projects using this or newer versions of cordova-androidcordova-ios 4.5.0+. The plugin was not needed any more.