Societies have made the poor better off by preventing people from becoming too wealthy, though. Specifically, I'm thinking of the very high high-end tax rates that were common 60 years ago.
Besides, someone creating more wealth than you do does not hurt you.
And I wonder what's behind that rhetoric twist in your second sentence. Was that on purpose or do you not even notice?
Because no, somebody creating more wealth than me does not hurt me by itself (I might even benefit!). Somebody accumulating and being able to command more wealth than me can hurt me, among other reasons because it gives them political power, which they can wield to hurt me and others. Inequal wealth accumulation taken to its logical extreme is undemocratic because it violates the principle of one person one vote.
(Some wealth accumulation is okay. There's room for nuance here.)
Example, please.