In plain words
The Kṛta Yuga and the Tretā Yuga: dharmamūlam idaṃ jagat. The world went on standing on Dharma. Step by step, by the time the Dvāpara Yuga came, it was dhanamūlam idaṃ jagat. What was the root cause of the Kauravas and the Pāṇḍavas going to war? The Pāṇḍavas asking to be given at least five villages, the Kauravas saying they could not be given: so this whole affair turned on wealth alone. Today, in the Kali Yuga, it is not dharmamūlam idaṃ jagat. It is not dhanamūlam idaṃ jagat. It is dayamūlam idaṃ jagat. Today there is compassion in no heart at all. It bears the name hṛt-daya, yet there is no daya in the hṛdaya. Today, for want of compassion, man falls into many hardships.
In the Kali Yuga, Faith in the Vedas and Śāstras Was Lost
Before this Kali began, in the kingdom of Kerala, where the Buddhist and Jain religions were widely spread, in a small village called ‘Kālaḍi’, a son was born to a couple named Śivaguru and Āryāmbā. What was the state of things then? The kings of those days marched on one another's kingdoms, tormented the people in many ways, and went on scrambling only after physical pleasures. It was because such wars were taking place that hatreds, one against another, went on forming in the minds of men. Through these hatreds unity wasted away. For want of unity, misconduct of every kind began. Injustice, lawlessness, misconduct, Asatya and violence grew and grew. Not stopping at this, the paṇḍits of those days, the knowers of the Vedas, the learned, the men rich in intellect, all of them went on inventing many meanings for the Vedic mantras. They changed the very form of the Śāstra completely. They went on teaching the Veda with a contrary meaning. That is why faith in the Vedas and faith in the Śāstras was lost. At that time someone was needed to raise them up again.