It is sad, but true, that some teachers (monastics or laity), having gathered some fame and status, become less active in participating in Dharma retreats, talks and classes, especially those conducted by others (monastics or laity) with less fame and status than them, even if the Dharma they share is more than that they know. Could it be an ego problem?
Perhaps they are busy teaching themselves? Perhaps. Perhaps they really think they already know enough? The best teachers are active students too – in one way, another, or more. Perhaps they have other ways of learning? In some cases, as teachers, they become less active in conducting Dharma retreats, talks and classes too. Perhaps they are busy practising? Let’s hope so. May all be ever more diligent in learning, practising, realising and sharing the Dharma.