Browser defaults are crazy
I could use you as a bot to assault web services I dislike, utilize some of your compute to calculate stuff I’m interested in or mine cryptocurrencies. I could use it to gather enough information about you that I can recognize you from a different browser or private mode. I could run P2P (peer to peer) software to have you help serve content I want to spread. Oh and how nice of you to leave this tab open for a while before you had time to read it, right?