Wealth inequality is more about the influence money has in both micro and macro-economic and social contexts than "I want what they have". Its no different than how other monopolizations work - the more of a supply you hold, the more distorted the market is around you. The same applies to money. Except money impacts all aspects of society, all markets - it gives you a greater voice in government, gives you influence over the lives of upwards of billions of people, etc. Just taking away that power from private individuals is often by itself a net positive for liberty.