It is just like TOEFL, GMAT or ISO.
It sets the standards such as which side you should wear your name tag.
It allows a multinational to hire different trainers in different countries to train towards the same standard. No wide-scale training is possible without a standard.
The IITTI standard sets the "what" to be delivered. It is up to each trainer to design the "how" to deliver it.
That is, your creativity and your brand can flourish from the "way" you deliver. Something uniquely yours.