If humanity goes extinct, wouldn't there be nothing for God to do?

This question is really philosophical and deep. To put it simply, "If humanity doesn't exist, do transcendent beings like God or demons also become meaningless?" This depends on one's religious views, ontology, and anthropocentrism.

The 'God' or 'demon' we commonly refer to is mostly defined within the context of human relationships. For example, God listens to prayers, forgives sins, guides humans, and judges.
Demons are portrayed as beings that tempt, corrupt souls, and deceive humans.

But what if humanity completely disappears?

Both God and demons would lose their subjects. There would be no prayers, no one to tempt, no sins, and no salvation.

In this case, there are two perspectives:

Anthropocentric perspective: God and demons have no meaning without humans

This is the way we commonly think. "God is a creation of humans." In other words, we have created God. The concept is that if humans disappear, both God and demons would also vanish. For those with this philosophy, God and demons are symbolic beings that can only exist with humanity.

Transcendent perspective: God and demons exist even without humans

From a religious perspective, this is more common. God is the creator of the entire universe, including humans, and humans are just one of His creations. Therefore, even if humanity disappears, God continues to exist for His own reasons and purposes.

The same goes for demons. Tempting humans is just a part of 'evil', and demons may operate in a larger order of existence. For example, they could exist for other dimensions, other life forms, or some cosmic purpose we are yet to understand.

An interesting thought

Would God and demons get bored?

"If there are no people, no prayers, and no sinners... what do we do now?"

Thinking along these lines, it seems that God and demons might ultimately be beings that have meaning within relationships. Roles and meanings arise only when there is someone to observe them.

"If humanity goes extinct, the existence of God and demons will depend on how humans define them. If we see them as symbols, they will disappear with us; if we see them as absolute beings, they may still exist."