FL Studio is great for quick audio editing, where you need to quickly make an edit to a song or add a new part to an existing song. Due to the included audio processing plugins, there is no need to purchase more to increase the software's capability. These features lend it to "out of the box" solutions, where quick implementation with no hidden costs is important. For serious audio editing and mix down, FL Studio is not well suited, as it is designed to be a good all round music creation software, rather than a dedicated audio editor.
I gave it the above rating because it is an incredible software for music creators and even though it might be hard to use at first, but once you get the hang of it, you will never be troubled again, and in all honesty, nothing comes easy life, especially if one yearns to become good at. Same applies with FL Studio. In conclusion, it is a great software.
Audacity is a free open-source software that is only for recording and editing some audio, while FL Studio on the other hand allows you to create your own music, record your audio, edit your audio and many other features all for a small price. FL Studio has way more effects pre-sets than Audacity. Even though Audacity's recording features can come close to FL Studio, there are many other factors that led to me opting to invest in FL Studio. Many other music producers also recommended FL Studio; therefore, that's what I chose. I have used both software for almost 2 years each, first being Audacity and then I decided to get FL Studio and have been using it for all my audio recording, editing and music making ever since.
Like I mentioned beforehand, it is slightly expensive but if you think of it, it is a lifetime investment.
FL Studio is also essential to have if one wishes to create music of their own or background songs because that way, you won't have to pay someone to create music for you.