How does a husband choose a wife based on her lineage, considering that clans include both the righteous and the unrighteous, and that the choice is for the person herself, not for her clan, so what is the benefit of lineage in this case?

The Prophet, peace and blessings be upon him, set the standard for choosing a wife by saying: "A woman is married for four reasons: for her wealth, for her lineage, for her beauty, and for her religion. So, choose the religious woman, and you will prosper." His statement "for her lineage" is an informing about the reality of people's choices, not a command to choose a woman of good lineage. The intention is that lineage should not be prioritized over religion and character. However, if a woman possesses both religion and lineage, that is preferable.