And the point several of us making is not that. The point is that designing a class that doesn't take the fictional conceits of the concept it is built around into account is unlikely to produce a satisfying result. Taking a chassis designed for an entirely different type of fiction and filing off the serial numbers even less so.
Obviously, this is an opinion, and clearly it is not universal as evidenced by the 27 pages of this discussion. But the relation to real science isn't the basis for that opinion.
But that's pretty easily disproven.
Casters in D&D do not emulate fictional conceits. Like, at all. I cannot think of a single fictional example (outside of D&D fiction of course, but, even then, usually not) that follows D&D casting rules.
Never minding the combat oriented classes using a combat system that is pretty much entirely abstracted and actually follows virtually no genre conceits. The complete lack of "stunting" mechanics in most version of D&D is a good example here.
The classes are not, and nor have they ever, been built around the fictional conceits of a concept. The classes are built around making the game fun. Any fictional conceits come a very, very far second place to that primary goal.
And that ignores the fact that the "fictional conceits" of psionics is an incredibly broad category. Do we mean psionics like Babylon 5 - where it's more or less just telepathic style powers? Or do we mean something like Dune where psionic powers can move you across the stars? Or psionics like Star Wars where it is very much just magic by another name and can do anything you want it to depending on the needs of plot?
So, I guess the basic question is, if you want to fit fictional conceits, "which fictional conceits"?