To me, it seems objectively easier to pull into a parking space forward and then back out of the space when you are ready to leave. You don’t have to line up with the lines while driving backwards, and it’s easier to keep from hitting other cars as well. So why back in? To me, the only advantage I can think of is that you can get out quicker, technically.
Edit: I do not need driving instruction, just wondered why. The reasoning.
Safety - pure and simple. Visibility is much poorer in reverse an you are more likely to hit someone or something you can’t see - and there a lots less potential hazards like cars zooming past or an errant pedestrian (especially children) in an empty parking spot than there will be in the pathway / roadway when it comes time to leave.