Nobody said it was inferior, but when you are talking validity, truth and knowledge (let's put aside the sage wisdom and insights) "messing with processing of information" as you say could be easily seen to suggest that the knowledge we may think we gain may be compromised as it is by definition also messed with.
While psychedelia is different from "true deleriant hallucination", I'm - for example - still pretty sure the explanations for seeing kaleidoscopic colors are much more plausibly found in the affected visual cortex processing; considering one of the most certain thing we know about psychedelics is that they are chemicals that influence brain function... more plausible than, say, that we can finally "see colors in a wider spectrum that is ultimate reality". That is definitely a more romantic idea, but there are many more similar phenomena like migraine aura's with zigzag OEVs, and those also only tend to be explained as magical or divine by tribes unaware of neuropharmacology. Ancient beliefs will also have to confront Occam's razor.
The point of that is: while seeing things like colors you've never seen before is interesting and offers insight in many things like the workings of our visual cortex in different modes, any knowledge we think we gain from that is tentative and instead more likely to be misinterpreted in ways we would love to be the truth.
In that sense, experiencing more sensory illusions and cognitive delusions can give us a whole lot of insight into the illusory nature of many things we experience sober and take for true and for granted.
Therefore I agree with you(!) that when sober we don't have a true picture of reality either because it is always subjective to begin with, observation in itself is empty (as a machine may do) and pointless; interpretation always colors our perception, once we determine what we choose to look for, functionally, we are already filling in things that are not strictly there.
Learning how to cook while tripping is not knowledge gained FROM psychedelia but a skill / information gained WHILST tripping. Psychedelia can stimulate creative imagination, that can allow us to come up with for example ideas for recipes we never thought of before but that again is not something we suddenly know, just something we intuitively think could be interesting to pursue and it very well may be.
But if during a trip you have CEVs of something compelling happening, that is not necessarily more or less true that something different we imagine or dream even if it more complex, novel or convincing than normal.
What should actually be convincing is what holds up when we test it and attack it. How many people have the guts to really experiment, test and attack their beliefs and see how well they hold up?
As I said a few times now: the issue is with filtering what is sensible which is very hard or impossible to keep up with realtime. I have extensive experience with losing skepticism in favor of creative imagination (during periods of very frequent tripping), and that is not supportive of theories or models that are true or purposeful. More on this as a tangent:
So yes: creative imagination for ever more farfetched, complex, interconnected ideas certainly happened when I tripped a whole lot, but none of it was gained knowledge until I combined it with skepticism and research. That is why I conclude that insight can be gained and creativity in art, science, philosophy and other fields may be stimulated... but knowledge is not gained FROM psychedelia, just a jumble of ideas both valid and invalid that need to be filtered sooner or later, because deep, profound and out-of-the-box thinking may be awesome but it is just from big leaps between neuronal branches of your mind that is indifferent to validity. And that is why it starts counting as knowledge only when it is processed some more and reality-checked.
One of the nice things it did for me is catalyze my tendency to think of absurdist jokes and cartoons fueled by hyperassociation.
