I hate to break it to you, but most of SMT really doesn't have any core unique mechanics compared to other wizardry clones.
Megami tensei and anothet jrpg that i forgot the name of invented and made popular the whole genre of recruiting enemies to fight alongiside you.
Withough them you wouldnt even have shit like pokemon
First person Dungeon crawlers are more or less a relic of the past. Being able to move in 4 directions is something that really puts off people(also the fact that Dpads are now mistly used for menu control and not actual movement) and the fact that you can't see your party while moving gives it a real claustrophobic feel that people just don't like. It's the reason why all other attempts at revitalizing OLD SCHOOL Dungeons Crawlers essentially failed.
They used the first person due to limitations of its time, and hasnt been a thing since nocturne (not counting strange journey, because that was a deliverate return to roots game)
There's been so much advancement in the genre from a mechanical standpoint that to try and reject persona fully would mean to cripple the gameplay.
Persona hasnt added jack shit to the formula other than a i win/do a lot of damage button
It still uses the barebones digital devil saga system, and even then DDS manages to be more complex than both shitsona 4 and 5
People basically just like SMT for the art style, but try finishing shit to 100% completion like you would a persona game.
Doing a 100% smt game no matter if its mainline/spinoffs is tedious due to requiring fussion accidents to get some of the demons and you are pretty autistic or bordeline stupid to even consider the compedium a requirement for 100%
Noctourne is notorious for needing save states because the demon fusing is a lottery.
Its not a lottery, there are recipies that still carry back from smt 1 to get certain demons, unless you want to say its a lottety to get the skills you want on the demon you want.
And even then that was so you wouldnt relly on a single demon for the entire game and to experiment with your party composition, seeing as how these games would be easy to break if you could just get what you wanted (see how easy it is to break golden/smt 4/persona 5)
If they want to make SMT have broad appeal they need to use persona's demon fusing mechanics and how they do the bargaining.
God you are fucking retarded, im not even gonna bother with this one
Make it a full on 3D dungeon and have the Overworld be fully explorable like Dragon Quest 11 or Final Fantasy did it.
The overworld has been fully explorable since smt 1, and they have made them 3d since fucking nocturne
Also make the 3 endings quantifiers Law, Neutral, and Chaos be visible at all times so people can change their allegiance by making informed decisions and tie that to shit like quests. Because another thing people have zero tolerance for is unknowingly getting into an end state and missing shit.
That shit is already in since the allegiances were introduced, and you do realize chaos/nootral/law arent your typical good/i dunno/bad answers right?
Besides, you can check which alliance you are by the rotation of your character icon, and every fucking game that has the alliances tells you this