The noun complacency means the state of being contented or satisfied about a situation.

Synonyms are satisfaction, contentment, smugness, or sense of security.

The word origins from 1640s, from same source as complacence meaning “pride, arrogance” but with the later form of the suffix –cy.

Her complacency is absolutely irritating.

I want to avoid his complacency whenever he talks about his independence.

We can say that the cause of the issue is the complacency of the government.