Quoting from Mitch Vogel’s Nintendo Life review of the Persona 3 Portable re-release for Nintendo Switch:

We appreciated the overall darker tone of this narrative [compared to Persona 4 and Persona 5], as death is a frequent theme that informs the events and decisions that take place over this 60+ hour story. That’s not to say P3P is missing its moments of levity—there’s certainly plenty of the lighthearted high school antics many fans of the later games will be familiar with—but there’s a much heavier and more menacing vibe to the plot here. This doesn’t necessarily make it better or worse than the later releases in the series, but we did appreciate how it gives P3P its own distinct kind of identity.

Persona 3 FES was my entry into the Persona series. Portable was a remake of FES, adding the ability to play as a female protagonist (interesting) but greatly simplifying the visuals and removing the FES-exclusive epilogue (bad and very bad). While FES is the definitive version of Persona 3, it does feel primitive in many respects compared to Persona 4 (the best of the three on the whole, see my thoughts on the Dojima and Ai Ebibara social links) and Persona 5. But I agree fully that its “darker tone” distinguishes it from its successors in a good way. While the Persona re-makes and re-masters are perhaps already too numerous, Persona 3 FES (with the full epilogue) would be interesting with a new coat of paint and some enhanced social links (the girl route has notably better links than the original).