The Meaning of Life, the Universe, and Everything.
Depends on what server you are using it for. I just recently installed Lunar Client to play on Hypixel but Lunar is banned on most other servers because it messes with their anti-cheat systems. So, Lunar is best for Hypixel, and Badlion is best for other things like Mineplex or even single player. I just use Lunar all the time since I am too lazy to install Badlion.