In the famous words of Dana White, 'styles make fights'.
When you create a fighting promotion that invites people from all over the world to test their variations of martial arts against each other, a diverse and unpredictable chaos is to be expected.
In a world of this much diversity, some martial arts will be more successful in the Octagon than others. For example, wrestling and jiu-jitsu have been found in the tool kit of multiple world champions, but who can you remember winning a title with Kung Fu? (And that's not a knock on the style.)
A lot of fighters will adapt a martial art to fit their needs and develop an unorthodox interpretation that can reap rewards. Conor McGregor's amalgamation of capoeira, jiu-jitsu and boxing springs to mind.
It's all down to trial and error. Some incredibly talented fighters just can't find the winning formula in the cage and some invent a new discipline altogether in the hope of discovering the next MMA craze that another generation will then equip themselves with.
Styles are like fashion and some of them can be downright weird to behold - like these odd attempts at scoring a 'W' in the UFC.