What are some impacts of the head of household filing status benefits-detriments both intended-unintended?

Individual Taxation-Income, Exclusions, and Filing Status

What are the fundamental purposes of filing statuses in the tax system?
Which of Adam Smith’s principles of taxation do filing statuses provide to the tax system? Why?
Who in our society would benefit or suffer if the head of household filing status is eliminated? address both groups
What are some impacts of the head of household filing status benefits and detriments both intended and unintended?