According to Vishnu Purana,
In Jambu-dwípa, Vishnu, consisting of sacrifice, is worshipped, as the male of sacrificial rites, with sacrificial ceremonies: he is adored under other forms elsewhere. Bhárata is therefore the best of the divisions of Jambu-dwípa, because it is the land of works: the others are places of enjoyment alone. It is only after many thousand births, and the aggregation of much merit, that living beings are sometimes born in Bhárata as men. The gods themselves exclaim, "Happy are those who are born, even from the condition of gods, as men in Bhárata-varsha, as that is the way to the pleasures of Paradise, or the greater blessing of final liberation. Happy are they who, consigning all the unheeded rewards of their acts to the supreme and eternal Vishńu, obtain existence in that land of works, as their path to him. We know not, when the acts that have obtained us heaven shall have been fully recompensed, where we shall renew corporeal confinement; but we know that those men are fortunate who are born with perfect faculties in Bhárata-varsha."
It also says
From this region heaven is obtained, or even, in some cases, liberation from existence; or men pass from hence into the condition of brutes, or fall into hell. Heaven, emancipation, a state in mid-air, or in the subterraneous realms, succeeds to existence here, and the world of acts is not the title of any other portion of the universe.
But it doesn't look correct in today's context. There are many people in India who are doing crimes and acquiring bad Karma? Indeed, if we acquire Karma on this land, how can we liberate?
Also, this answer gives info about other islands and all people on this Earth were descendants of Grandsons of Priyavrata.
- Why only descendants of Bharatha are privileged or Why this Varsha (country) is privileged?
- In Kaliyuga, Sanatana Dharma or Vedic Religion is limited to Bharatha Varsha alone. What about other Yugas? In other Yugas people were present in other islands and were worshiping Vedic Gods. Was Bharatha Varsha still Karma Bhoomi during those times?