The belief that there will be no more Buddhas in our present world is rooted in Buddhist teachings and is based on the concept of the Three Ages or Three Periods (Sanskrit: Trisāhasra-kalpa) found in some Buddhist scriptures. This belief is particularly prominent in certain branches of Buddhism, such as Theravada and Mahayana.
According to these teachings, a Buddha is an enlightened being who attains complete and perfect enlightenment (nirvana) and possesses the knowledge and compassion to teach others the path to liberation from suffering. Buddhas are extremely rare and exceptional beings who appear in the world at specific periods of time to help guide beings towards enlightenment.
The Three Ages in Buddhist cosmology are:
The Age of the Right Dharma (Sanskrit: Saddharma-samayika): This is the time immediately following the passing of a Buddha when his teachings are still present and understood correctly. During this period, people can practice the Dharma effectively, and there is a strong connection to the Buddha's teachings.
The Age of Semblance Dharma (Sanskrit: Pratirupa-dharma-samayika): In this age, the genuine Dharma taught by the Buddha has begun to decline. People still follow some semblance of the teachings, but the understanding and practice are not as profound or effective as in the previous age.
The Age of Dharma's End (Sanskrit: Dharma-antara-samayika): This is the time when the true Dharma has almost disappeared or has become entirely lost. It is believed that during this period, people will have little to no understanding or inclination to practice the teachings, and enlightenment becomes increasingly difficult to attain.
According to some interpretations of these teachings, the present world is considered to be in the Age of Dharma's End, and as a result, there will be no more Buddhas appearing until the Dharma declines and disappears completely. This belief does not mean that Buddhism itself will vanish, but rather that the true and complete teachings of a Buddha will not be accessible to the people of this era.
For the future of Buddhism, it means that the responsibility for preserving and passing on the teachings falls on the followers and practitioners of Buddhism during this degenerate age. They are encouraged to uphold and practice the Dharma as best as they can, even in challenging circumstances, and to keep the teachings alive for the benefit of future generations. In Mahayana Buddhism, the idea of Bodhisattvas - beings who have dedicated themselves to attaining enlightenment for the benefit of all sentient beings - is particularly emphasized, and Bodhisattvas are seen as playing a crucial role in helping others along the path of liberation during this age.
It is important to note that different Buddhist traditions may interpret and understand these teachings in various ways, and not all schools of Buddhism may share the same views on the Three Ages or the future of Buddhas appearing in this world.