They should've had two difficulty modes from the start. Easy and Normal. Forcing only one difficulty mode and making it piss easy, was an incredibly stupid thing for them to do. I love the actual combat of the game, but it falls apart because there's no RPG mechanics and proper difficulty to support the combat and make it shine.
No buffs/debuffs, no elemental damage, no gear and set bonuses, no skill trees for you party members, it was just an incredibly backwards game. I'm pretty sure during development they thought the big set piece battles would carry this game hard. I'm replaying FFVII: Remake right now, and it's so fucking night and day the options and control you have to build your party members, compared to FFXVI. When Rebirth comes out it's going to really shine a light on FFXVI's shortcomings.