There is a google chrome extension titled Nuke Reddit History. Running this before deleting your account removes all your old posts. Your old posts are content that Reddit is monetizing. Deprive them of that money and wipe clean your account prior to deletion. Or my personal favorite method: Get your account permanently suspended by messaging the mods on /r/politics over and over and posting pro-Trump memes in the comments of anti-Trump articles on every subreddit you possibly can.