What nonsense. Of course 2D (or 2.5D) games have a future. Or at least they should have.
Each project has a budget. Each project has limited resources. It is foolish to waste these resources on meaningless things.
Creating a 3D RPG is more expensive and more complicated. If you can give up 3D - and instead add more content to the game, more dialogues, more mechanics, etc. - it should be done this way. A similar problem is dubbing of dialogues. It adds little to the gameplay, but it greatly limits the amount of text you can implement.
Games with relatively primitive, minimalistic graphics often offer us more possibilities than graphically advanced games. For example, in Divine Divinity we can destroy or move most of the objects in the game world: barrels, chests, boxes, apples on the table and dishes in the cupboard. At the same time, the geometry in 3D games from the same era is completely static: most of the boxes and crates are just decorations. Even today's 3D cRPGs are often much less interactive than many old games. Ultima 7, Divine Divinity, Dark Sun or ADOM allow us to perform a much larger number of activities than Skyrim or Witcher 3. Of course - do not overdo it. Not every game should be a roguelike. Nevertheless, I would postulate a general rule: graphics in cRPG should be primitive enough to not limit gameplay.
Pillars of Eternity is not a perfect game, but I like it anyway. I don't really see how 3D graphics could improve this. Art-style would probably be uglier, the locations would probably be less numerous, the fights would not change (except that we would play with unnecessary maneuvering the camera - exactly as in NWN2).
3D RPGs are fine, but only if designers have an idea how to use 3D. And this happens rarely, I believe.
How many cRPGs actually makes use of three dimensions? For example, Wizards and Warriors comes to mind. The dungeons in this game are designed with three dimensions in mind - there are plenty of elevators, bridges over chasms, underwater corridors etc. These dungeons could not be transferred to a 2D engine.
Another example is Divinity 2: Ego Draconis. The exploration in this game is both vertical and horizontal. We visit external locations on foot or as a dragon. We fly up and down to get to hidden places. Many dungeons have a tower-like structure where platforming elements are an important part of exploration. Even some puzzles are based on the players ability to move in three axes.
But these are exceptions. Most of the 3D RPGs are in 3D for purely decorative reasons. Games like NWN 1 and 2, Drakensang, Original Sin, Dragon Age - get nothing from being in 3D. Every dungeon and every fight in these games would be easily transferred to a 2D engine.
TL; DR: If game developers have an idea how to use 3D to improve gameplay - that's okay. But if 3D is just an ornament, it is a waste of time and resources and it disrupts gameplay.