Paper Trading vs Backtesting: They Answer Different Questions
Backtesting and paper trading are both ways to test a strategy without risking money, and they are not two grades of the same thing. They answer categorically different questions, one about the past you can see, one about live conditions you have not, and each has its own failure mode. Treating them as interchangeable, or treating either as proof a strategy will profit, is how traders talk themselves into confidence they have not earned.