I don't remember if I thought the dungeons were too long or not.Â I don't think so?Â Maybe the Casino one?
Maybe not too long individually, but the game itself is too long IMO, and more importantly with too many downtimes in the middle. The pacing is a problem. It took me 2 years to finish it because a lot of time I put it down during a less interesting moment, and didn't feel the need to come back at all. They start very strongly with the amazing first Palace, other ones like the Pyramid are awesome too, but some of them are pretty useless and uninteresting (you could erase stuff like the Bank from the game and lose basically nothing). And the fact that you have to go out of each Palace once for a useless cutscene before coming back in is a bit annoying and cut the progress. I would have preferred if the Palaces were linked to the team members to add depth to the main characters instead of villains who disappear from the game after the boss fight.
P4G had a poor start, but after that it was strong all along. Took me months to pass the 4 hours mark, and then 5 days to finish the game in around 70 hours. Around 130 hours to beat P5 is too much for a comfortable normal run (I would have preferred if some of it was optional).