Why are there so many different paths?

I will admit I am just starting to look into buddhism and such. I am confused because so far I understand that the Satipatthana sutta provides everything anyone needs to become 'enlightened'. If that is the case, then why is there so many different forms of buddhism (including the tantric one) each with various meditation techniques etc? If the Satipatthana sutta (or Anapanasati sutta) are the 'bread and butter' of buddhism, why would anyone need anything else/different to achieve their enlightenment? Its like, if something works then why even bother changing it up?