While other philosophies confine realized souls to heavenly realms and other Lokas explore the Mind - Blowing Concept of Jivan-Mukti in Sanatana Dharma

If the waking state is like a dream, why would the awakened ones (the realised souls) help dream-people who are unreal anyway?

According to the philosophy of Vedanta, there are
three types of reality the Absolute (paramarthika), the empirical (vyavaharika) and the apparent (pratibhaşika). Though from the standpoint of Absolute (Brahman) the two states, empirical and the apparent do not exist, to the one who has attained the Absolute, there may seem to be the empirical and the apparent. In the empirical state, human beings exist in samsara which consists of births and deaths. Those who exist in this empirical
state cannot attain the Absolute unless they gain the grace of those who have attained the Absolute experience.

Even in those who have attained the Absolute experience, though they experience the same entity, there is a possibility of taking pity on those who exist on the empirical level without attaining the Absolute and bestowing their grace, since the empirical state continues to exist as long as they are embodied in the world. In this manner, only in Sanatana Dharma, the bestowal of grace on the individual who exists in the empirical state by the person who has attained the Absolute consciousness, occasions the possibility of uplifting the former.

In all the other systems, it is not possible for the realised souls to descend to the earth and uplift people, since they are said to attain the highest status after reaching Heaven. Because, according to these systems, only God can descend from Heaven and become incarnate. Those who have attained liberation do not incarnate themselves. Those who have attained the Absolute cannot descend and uplift the individual selves of the earth. But in Advaita, there is nothing like reaching Heaven and attaining liberation. Even on this earth, after attaining Absolute knowledge, jivan-mukti or liberated-while-being alive, it takes time to attain videha-mukti or disembodiment after realisation. In this time interval, to convey even to the laymen the realisation gained is possible in Advaita.
Therefore, though philosophically there is only one Absolute Reality, in the life of those who have attained that Reality i. e. jivan-mukti it is possible to bestow grace with great kindness on those who exist in the empirical state, till their body is seen on earth i.e. till they attain videha-mukti. courtesy ahambrahmaasmi. org
Prarabdha Karma is the cause of the present birth and the experience of pleasure and pain in this life. After the attainment of the knowledge of the Self, sancita-karma and agami-karma without following us, get destroyed. Prarabdha-karma alone persists even after the attainment of knowledge, till the body is resolved.
Hence, the enlightened one eats daily like us, sleeps, bathes and performs all types of deeds. He does not act with attachment and egoism like us; his bodily organs alone function. The fan rotates speedily when we put on the switch, but even if we put off the switch, it stops only after some time. When the organs function along with sancita-prarabdha, attachment, etc. exist. When sancita-agami disappear, body, organs, etc., function without egoity and attachment due to prärabdha. Thus, the enlightened one performs action, without the sense of I and mine in order to guide the common man to the state devoid of the sense of 'I' and 'mine'. Whoever wants to reach a particular state, can be made to attain that state, only by those who have already attained that state.
- From the Voice of Shankara