People try to make these all the time, and invariably they are never, ever completed. There are even scripts/plugins for stuff like Social Links to make the programming and interface a little easier, not to mention a couple of scripts/plugins that allow for random dungeons if (like me) you're more into the P3/P4 dungeons than P5's handcrafted style.
What everyone always forgets is that Persona's appeal doesn't come from its system so much as its content. Persona games have double-digit hours' worth of made-from-scratch, non-scalable, painstakingly crafted story content and slice-of-life content that takes a whole team years to make, and sharp, witty writing that comes from some of the best creative talent in the video game business. Without both the expansive content and the writing, Persona would fall flat.
It's very unlikely that any single member here has the both the talent and the incredible amount of time it would take to construct that amount of high-quality content, and I'd have a hard time envisioning a team made of members here being able to align in their creative visions (and avoid real life's commitments scuttling the project) for a length of 3-10 years to see it through to completion. It would be reasonably easy to make a little tech demo that shows off the gameplay and has maybe 5% of the game's projected content (with most stuff just saying "inaccessible for now"). Expanding that little by little to 100% of a real Persona-like experience will be the biggest grind you take on in your life.
So in short, there's massive interest in such a game from the RPGM community, but I don't believe it's a feasible RPG Maker project. Any small part of it could be done easily, but creating the whole thing would be Sisyphean.
