I think it's fundamentally flawed to make a comparison by time frame. Why? Because the release schedule for 5e is much slower than in previous editions.
5 years is 5 years.
It's not like 5e is going to release everything any given faster-release edition did, in the same order. It's not like any of us are getting any younger, either.
so let's look at a dedicated psionics class
Let's look at playable psionics, since we don't have that in 5e, after 5 years of waiting
, and how long it took to find itself as an official class. Looking at products excluding adventures
2e: 15th product released (complete psionics handbook)
3e: 11th product released (psionics handbook)
4e: 49th product (PHB 3)
26th book, by my count, even including little things like dungeon delve & races supplements. How did you double it? Include miniatures or something?
Also:
0e: 6th product released, Eldritch Wizardry Supplement III
1e: 2nd product released, Player's Handbook
5e: 13 products so far
so when you look at it like that, it's not like 5e has forsaken the psion just because its 5 years in so far.
5 years is 5 years. And, if Eberron, had also had the Psion, at product 13, that would have put 5e in the middle of the pack, as far as books in print before seeing psionics goes, between 3e and 2e, which, really, would be appropriate.
But 5 years is more than twice as long as any other edition took. 0e and 1e had even slower paces of publication, and they both had
playable psionics, in print, a year or two in. Heck, if you don't count playable, 1e had psionics
at launch.
Five Years. It's five years, no matter what how you handwave or misdirect or move the goalposts...
...and counting.