As strange as it sounded, Yaggdytha needed time to spread his control over the fabric of time. It was just how a king needs space to rule a kingdom. You can't own space without land, and so he couldn't dominate time without an extension of it.
But his elemental expansion, a skill that he had learned in the past thousand years, allowed him to bypass that restriction and instantly establish his domain as long as he got enough energy to do it. Time and space were intertwined like fabric; if you pull on one, the other also gets dragged. So when he established his elemental expansion, time stopped flowing for everyone, space itself became a prison, and both Arad and Gojo found themselves stuck in their place.
