I played the modern Persona games in order of Steam release, from 4 to 5 to 3 (skipping Portable because of rumors of Reload), and the fact that people can play Persona 3 and still prefer 4 or 5 only further proves that Persona fans can't read. 4 in particular. Jesus fucking Christ if I played the orignal Persona 3 when it came out and then played 4 after I probably wouldn't have played 5 at all.
Every game mechanic, from the Arcanas to the Social Links to the very Calender system that the other modern Persona games specializes in, all feel like an integral part of the experience, as opposed to a gameplay aspect or a method of progressing the plot. The decision to change from a specific date in which a major event will occur to a simple deadline that can be done at any point beforehand between P3 and P4 is one that has had irreperable consequences on the impact of the very Calender that P3 first concepted, despite being the first (modern) game to do so. In general, P3 utilizes and even plays around with its gameplay mechanics in a way that the other games could only pretend to do to the same extent. I have minimal experience with the original release of P3/FES, but I doubt that much differs aside from key quality of life changes and Direct Control of party members, which I think wouldn't have factored too much in my enjoyment nor my experience of the game anyway.
There are still a number of problems I had with the game. Social Links were overall written or implemented better in Persona 5 (Suemitsu is genuinely the worst SL in the series), despite having a few standouts like Akinari and Bebe. Tartarus becomes a really egregious chore, especially in the endgame where it feels suboptimal to not go to Tartarus every night and grind to at least a full Arcana Burst, which leads to long slogs where the only reason you're there is because you feel like you're wasting time doing anything else. And the central plot has a number of weak points, most prominently the "twist villain", the way new party members simply just showed up and were expected to be a part of the gang now, and the extremely dry and even somewhat forced arrival and subsequent befriending of a particular new student, as well as the general repititiveness of major events up until Hanged Man, but that fucking home stretch was worth it.
In conclusion, I truly owe you an apology Persona 3 fans. I actually was not familiar with your game.