Final answer:
The Buddha remained on earth to teach others out of compassion and emphasis on personal responsibility, assisting them towards enlightenment and the alleviation of suffering.
Step-by-step explanation:
The Buddha, known as Siddhartha Gautama, chose not to pursue ultimate release (nirvana) immediately after achieving enlightenment but instead remained on earth to share his teachings with others. One core reason for this decision lies in the compassionate nature of Buddhism which places a significant emphasis on helping others achieve enlightenment and alleviating suffering. By accepting the Four Noble Truths and following the Middle Way, which represents a life of moderation between extreme asceticism and indulgence, individuals can work towards enlightenment and nirvana. Buddha's decision reflects the focus on the importance of personal responsibility and the willingness to assist others on their path to enlightenment, instead of solely pursuing one's own liberation from the cycle of rebirth and suffering.