Why didn’t Krishna remain with His devotees on earth?

“Krishna is compared to sunshine, and maya is compared to darkness. Wherever there is sunshine, there cannot be darkness.” (CC Madhya 22.31). While Krishna was still present on the earth it would be impossible for Kali-yuga to fully manifest. Indeed, the Srimad-Bhagavatam explains that when Krishna departs from this world, knowledge (jnana) and religion (dharma) go with Him, and the age of darkness truly begins.

But this may raise another question: “If Krishna came to establish religion, but religion leaves when He departs, then doesn’t that defeat the objective?” The answer is ‘no’: “This Bhagavata Purana is as brilliant as the sun, and it has arisen just after the departure of Lord Krishna to His own abode, accompanied by religion, knowledge, etc. Persons who have lost their vision due to the dense darkness of ignorance in the age of Kali shall get light from this Purana.” (SB 1.3.43). Although the cosmic cycle of degradation must continue, Krishna left a way and means to escape.