No. No, no, no. Nonononononono. Spells cannot be psionic powers or vice versa.
I do respect that opinion (I don't think psionics can be spells in the fiction), but I'm still trying to figure out precisely where it's centered. Which editions of previous psionics are you familiar with? Of the ones with which I'm familiar the presentation of psionic powers has been done in the following manners:
1e) Psionic powers are discrete things that cost a set amount of points to activate and have effects described similar to spells, but are not in fact spells. In some of the descriptions, it directly references spells from the the PHB, such as "This discipline [the psionic power
clairvoyance] is the same as the magic-user spell,
clairvoyance (q.v.), except that unknown areas up to 20’ distant can be scanned." Points recover gradually over time.
2e) Same as 1e, except I don't believe there are references to PHB spells, instead just writing up the entire effect. (I don't have current access to the 2e psionic rules, so I'm going by memory on this one. I also didn't have the later 2.5e revision, so I don't really know what was different in it.)
3.0e) Mostly the same type of presentation as 2e. Psionic powers now have levels that are equivalent to spell levels. Power points recover all at once in the morning.
3.5e) As 3.0e, except that many psionic powers directly reference PHB spells again like they did in 1e, and some powers can be augmented by spending more points to get increased effects. It tells you what happens when you do so inside the power description (essentially the exact same mechanic as 5e's "at higher levels" element in many spells, but with points rather than slots. This was almost certainly the original inspiration for that element in 5e spells).
4e) Powers mostly use the universal AEDU setup, except instead of Encounter powers they could use points (I think?) to augment At-Will powers to do extra stuff.
So unless Eldritch Wizardry or the later 2e revision did it completely differently, psionic powers have always been
mechanically analogous to spells. What has also always been true is that in the world they are
not spells. They are are something different that uses similar rules structures. (Editions have varied about whether or not they were considered
magic, with 3.5e treating them as a type of magic by default, and the rest treating them as not magic).
Where do you feel the line is where psionics become too closely connected to spells to be acceptable? Does it make a difference that in 1e and 3.5e they directly said "same as <spell in PHB>" after describing the uniquely different psionic elements, while in 2e and 3.0e they reprinted the text from the PHB with a few changed words instead? Or do you object to all of those editions' (1e-3.5e) presentations? (If so, I'm assuming you're basing your preference on 4e?)
For me, I have no problem with mechanically representing psionics with spell statblocks like they've done for half of the game's history. What matters to me is just that they preserve the important elements (both mechanics and fluff) that are different, like that they don't require incantations, gestures, and reagents because they sprout from inside of you without spellcasting trappings, and that they are not spells in the lore. It doesn't make one bit of difference to me if there is a psionic power called "explosive blast" and they write up it up and say it does 8d6 points of fire damage in a 20' radius, or if they they write it up and say "this power produces the same effect as
fireball" or if they describe how psionic powers work differently than spells mechanically and conceptually, and then provide a Psion power list of the the spells that mechanically represent the psionic powers the Psion class can call upon at various levels. D&D has done all of those sorts of things in the past. (I do have a preference against unnecessary reprints, so if a book is going to mimic something in the PHB with a few differences, I'd lean towards favoring them just referencing it rather than reprinting.)
I gave it high marks as well. Then at the end I told them that I wanted a Psion class of some sort. The UA was good, but it wasn't a substitute for a Psion.
I couldn't get past the psi die that I just don't feel works. I gave relatively good ratings for some elements of the Psi Knight, less so for the Soul Knife, and I had a difficult time knowing what to do with the Psionic Soul. I mostly assumed it would be the typical Dark Sun Sorcerer and that a Psion class would exist also, but even with that, I wasn't happy with some of what it did.