Animals in the zoo have keepers. Does an adult, sane human need one?
No, what God was asking Cain was, why did you murder your brother? And Cain didn't have a good reply, so he asked God if he was his brother's keeper. And God never said that he was.
Read it for yourself.
Genesis 4
8 Now Cain said to his brother Abel, "Let's go out to the field." [d] And while they were in the field, Cain attacked his brother Abel and killed him.
9 Then the LORD said to Cain, "Where is your brother Abel?" "I don't know," he replied. "Am I my brother's keeper?"
10 The LORD said, "What have you done? Listen! Your brother's blood cries out to me from the ground.
11 Now you are under a curse and driven from the ground, which opened its mouth to receive your brother's blood from your hand.
12 When you work the ground, it will no longer yield its crops for you. You will be a restless wanderer on the earth."
That’s the root of the problem. We are supposed to be responsible for ourselves...to be our own keepers.
Socialists want to be everyone’s keepers. They want to be responsible for others and have others be responsible for them.