Since Ionic 4 Full App is a huge project, you might not need all the plugins for all your requirements. Unnecessary plugins can cause issues with build, or at least cause the build to become heavy.
In most cases, you would want to remove a plugin from the project. Always remove a plugin using cordova CLI
$ ionic cordova plugin rm plugin-name
Sometimes user remove plugins by deleting the plugin folder from
plugins folder, but the plugin is defined in
config.xml as well as
package.json . Removing the plugin using the CLI removes all trace of it.
If you are modifying dependencies of a plugin, it is preferable to do it in
Modifying plugin in
plugins folder will not always work because on a new project setup, the plugin will again pick the dependencies from