What is the understanding of Allah Almighty's saying in Surat Yusuf: "And most of mankind, though you may desire it greatly, will not be believers"?

The summary of the answer: The noble verse: ﴿And most of mankind, much as you desire it, will not be believers﴾ [Yusuf: 103] was revealed as a consolation to the Prophet, peace and blessings be upon him, after the Quraysh and the Jews asked him about the story of Yusuf (Joseph), peace be upon him. He had hoped that this would be a reason for them to embrace Islam, but they went against his expectation.

The meaning of the verse is that most people will not believe, even if the Prophet, peace and blessings be upon him, strives for their guidance. Its explicit meaning is that most people will not believe, and its implicit meaning is that those who do believe are few.