Why is a guardian (wali) required for a woman's marriage, but not for a man's?

The requirement of a guardian (wali) for a woman, but not for a man, in marriage has considerations that relate to Islam's social and familial system. Although Islam equates men and women in honor, human value, and religious obligations, it has favored men over women in religious and worldly responsibilities, such as financial support and guardianship, as stated in the Almighty's words: {And due to them [the wives] is similar to what is expected from them, according to what is reasonable. But the men have a degree over them [in responsibility and authority]} and His saying: {Men are guardians over women by what Allah has preferred some of them over others and by what they spend from their wealth.}

Therefore, men were given the right to undertake the marriage contract as a duty and a benefit for the woman, to strengthen her position before her husband, and because her guardian is more knowledgeable about men than she is. This right is restricted by the impermissibility of forcing her to marry someone she dislikes, and by not preventing her from marrying (by withholding consent).