The pattern of a qigong, form, martial set or an application is not the final product.
It is the initial introduction to the material.

Many tai chi practitioners never progress beyond the pattern and remain perpetual beginners, regardless of how many years they practice.

It is vital that a student does not remain at the lower echelon of skill.
In order for the tai chi to improve, the pattern must be revised, corrected, improved-upon - not once - but as an ongoing process.
There is no final product, no graduation.
Even an advanced practitioner continues to explore and tinker with their practice.