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.
When pulling out, we are often more distracted because we have just been doing something else. Conversely, when parking, we are already in driving mode so it is easy to concentrate. Pulling put forward seems safer to me, as I can see everything so less likely to have an accident.
Also, it is normal where I live to reverse park.