None of this is mutually exclusive to a single entry system. Tracking where money is coming and going can be done any number of ways that is not double entry bo

None of this is mutually exclusive to a single entry system. Tracking where money is coming and going can be done any number of ways that is not double entry bookkeeping. These are also examples of cash basis accounting which is much simpler. When you get into accrual basis and revenue recognition especially is where the double entry stuff (IMO) just starts to break down. Meaningless accounts get invented just for the sake of having something to balance against, and your entries are no longer tied to actual money changing hands.