Qigong in tai chi

A tai chi beginner is not adept with tai chi so they need to do a lot of qigong. It provides the necessary fitness benefits by serving as a stopgap pending higher level tai chi skill.

An advanced student starts practicing the round form version of the Long Yang form. This increases the fitness benefits of form; allowing them to spend less time training qigong.

Neigong replaces qigong as the primary source of power. An expert is more adept with higher level tai chi skill, so they only do a small amount of qigong.

There is simply no need to stand for an extended duration since greater benefits can be gained through whole-body movement.