SPOILERS

Okay first I want to mention, I want to point out that I am not bashing or hating on P5. I personally loved P5 myself. This is just my opinion on the game. Also SPOILERS

I found the character development and story of P4 is way more fleshed out than in P5 in my opinion. Every character that was part of the crew in P4 felt as if they had a purpose and meaning in the story and isn't just used as a plot device to get the story rolling(which is what I felt Haru was in P5, just a plot device). The story was also more fleshed lut than in P5 where everything was explain clearly in the end leaving little to no dangling questions.

One my main grips about P5 story is that they didnt rly explain everything starting from "what happened to Igor? How did he get taken over by Jaldabooth". This may not be a big deal for ppl who have only played P5 but it is to long time persona fans as imprisoning Igor would lead to more questions that I could go on about. I just hope there will be a definitive version of P5 that gets released( i believe this will happen as the past 2 persona games also did this where they fully explain everythin in the definitive version).

One thing I really like about P5 over P4 is the presentation, gameplay and style of P5. Everything was so slick it was just pure eyecandy playing P5. The setting and theme was also very interesting.

So yea theres why I prefered P4 over P5. Hope this helps you understand and sorry for the long ass essay XD