But there are psions all over the 5th Edition D&D books. I've played several of them over the years...here's how I did it.
1. Petition my DM to use the Spell Points optional rule (in the DMG). Sometimes they say yes, but it's not a big deal if they say no. It just "feels" more like a classic D&D psion to me, but I can deal.
2. I like to start with the Githyanki
ancestry species (from MP:MotM). This is a matter of personal preference; any species will do. I've also done Human and Shadar-kai.
3. I usually go with the Sorcerer class, and the Aberrant Mind subclass (from TCoE). It's really the only sorcerer I play these days.
- Some folks want psions be Intelligence-based instead of Charisma. If so, choose the Wizard class and the Graviturgy subclass (from EGtW). It's a pretty cool subclass even if you're not going for "5E psion."
- Some folks want psions be half-casters instead of full. I don't, but if I did I would probably just take some levels of Fighter, Monk, or Rogue. Less work for everyone, right?
- Some folks want psions to be non-casters. I've played a couple...the Fighter class with the Psi Warrior subclass, or the Rouge class with the Soulknife subclass (both in TCoE). The PW is more fun than the SK, IMO, but YMMV.
4. And then I would always refer to my "spells" as "powers," my chosen class as "psion," and so forth.
But I get it, some people want Wizards of the Coast to ensconce the Psion class in the list of "official" D&D classes, the way they did with the Artificer. I guess that to them, it's less about getting to play a psion, and more about
having a psion listed in the official books...a way to make it more valid, more official. That's a good thing to want, but it has nothing to do with me playing the character I want to play.
And other people don't want Wizards of the Coast to create anything new, because of a litany of reasons involving gaming licenses, intellectual properties, and years-old grudges. The implication is that Wizards of the Coast will mess it up, has already messed it up, and the matter is settled as far as they are concerned. And...well, I don't know what to say to that. I'm playing D&D with my friends, not flexing my brand allegiance (or disaffection) to the greater gaming community.