They make it easy to get the right settings very quickly, without reading a huge manual. Plugins should just work. There are several presets for different types of video footage. These are settings we've found to work well in our tests and often work as is to fix flicker. If not, usually they just require minor tweaking.
Video plugins should make your life easier. The software should be doing the hard work behind the scenes so you can get work done quickly without watching hours of training videos. Flicker Free is not a plugin you need to use all the time, but when you do have flicker on video footage there's no need to re-learn it every time you use it.
No matter what's causing the flicker, Flicker Free can fix it. It was designed for Time Lapse videography, but works on slow motion footage, rolling bands caused by the camera being out of sync with LED or fluorescent lights, drone footage and more.