This is what I am hearing. The name "Psion" or equivalent is essential.
On the other hand I believe that with only one new class in seven years WotC has made clear just how little they want to add classes. And unless what the class is trying to do really isn't covered by other classes I think they have the right approach - and 5e sales are good enough that they also aren't going to make major changes.
They have also added psychic subclasses to the game meaning that a lot of psionic concepts and playstyles are covered. Which unless clear water can be found both thematically and mechanically between what's requested and what's already there makes a new class even less likely.
All of which means it's likely that WotC doesn't think Athas needs the Psion because there are already psychic characters in D&D. Which is just as well because if it did then Athas would be a lot less likely.
And the book that introduced psionics? Tasha's introduced three explicit psychic subclasses (soulknife, psychic warrior, aberrant mind) which means it may be the ramp up suggested.
When I asked what people wanted I was hoping to find something lurking that anyone even with no connection to D&D's history could see was clearly new and cool. Doesn't seem to be.
Clear water exists, Neon. You just can't see it.
Psionicists use Power points to pump their Talents, Disciplines, or Sciences. They don't cast spells. They can function as battlefield manipulators, healers, blasters, and Gish.
Hell. The name Gish -came- from Psionic Githyanki Warriors combining their psionic skills with melee prowess.
They're telepaths and telekineticists. They're Psychic Chiurgeons and Metacreatives. They use their will to directly modify reality rather than spellcraft and ancient languages.
There's a whole boatload of mechanics you could use to create a Psionicist class that feels vastly different from "Wizard" or "Sorcerer" to a similar degree as the Artificer or Warlock does.
Years ago I tried to build a proper Psionicist out of the Mystic mess. The first thing I did? Narrowed down the Disciplines list. Then I gave them a few unique abilities.
First, that they could use their Intelligence Modifier in place of any other modifier when rolling saving throws. It didn't give them -proficiency- in Strength saves, but made them marginally better at it than other characters would be on their poor saves.
Second, the ability to concentrate on two Psionic Powers at the same time. With a curated list of powers they couldn't stack a whole mess of crazy big fun stuff, but it was a neat twist that made them feel super different.
Third, Consumptive Power. Each day they could sacrifice a limited number of their Hit Points directly as if they were Power Points for use in powers. 10hp/long rest was the maximum. And it reduced your max HP by that amount, so having someone toss a heal didn't instantly fix it.
Add in some Psionic Quanta, which functioned similarly to Eldritch Invocations but could often be boosted with Power Points, and voila!
You had a unique and interesting class that wasn't a Sorcerer or a Wizard.
If I could do that, 3 years ago, based on the UA Mystic, surely WotC can do better.
