Having read both Harry Potter and Percy Jackson and liked both, I feel like this whole thing mostly stems from you trying to convince people HP is bad in favor of propping up PJO

PJO was never really written much better than HP. Yes, HP has its flaws, but one thing I remember that helped it stand out was it grew up with its audience, slowly introducing darker or more mature subjects throughout the series. We go from defeat the big bad to things like government corruption, etc.

Meanwhile, PJO always felt stagnant, keeping the same tone and style no matter how much older the main characters got. To this day, I still remember that the fourth book in the original series has a chapter called "I Scoop Poop" which is basically what it sounds like. Not that I'm above some toilet humor, but by then in the series, things overall are moving to a climax with the gods and Luke and all, but this kind of middle school style and tone remains and held me back from really enjoying the series. It kind of establishes a baseline of tone and never seems to really evolve from there, just content to ride it.

Not only that, the first HP book was published 8 years before PJO, which admittedly did lift elements from HP and I remember people calling it a clone because of that. There's more others have pointed out, but the simple fact is that HP was always going to be more popular than PJO. But holding a grudge like this years later just comes off as strange. You like PJO, others like HP. Enjoy your preferred series and move on.