Public wealth vs. Private wealth

So I watched a YouTube video showing clips of tik toks talking about the most insane rich person behavior. There was a clip of a guy talking about his job which is selling gold to investment firms and even Saudi royalty. Throughout the video he said that he worked with a person probably a politician in the Philippines who had more money then Jeff bezos in his bank account. (Not sure how true but wouldn’t be surprised). It just got me thinking like we really don’t know how much money there is in this world and how can anybody accumulate this much wealth. There is public wealth and then wealth we will never see. Is this money from slave labor/child labor or exploitation of underdeveloped countries??