Your argument in a nuttshell is in essence, if I may attempt to steelman you:
(large) hierarchies tend towards corruption: therefor large hierarchies (potentially) bad
I agree. unfortunatly for you (and me), the formation of (large) hierarchies are an essential part of the human condition, at least as a species.
They're essentially inevitable/unavoidable.
Yours (and mine) only salvation are systems that are least prone to that due to way they're setup. But any sufficient lare/powerfull human insititute (which can also be science though a distinction needs to be made between science as an insitutional body and science as a methodology) is, sooner or later, prone to corruption.
this is not an aspect of the systems in question so much as it is a human aspect. Your problem is it seems more with humans and how they function, instead of the symptoms of that in the form of either religions, or government, or schoolyard bully-clubs. or certain scientific institutes publishing research on how smoking is actually good for you etc..
That being said: despite all the fundamental flaws, (if you'll endulge me in giving you a small, but still potentially significant little white pill)
We've still managed to evolve as a species into something capable of wielding not only great malevolence, but compassion.
We've not only tamed/used and abused nature, but also protected it, repaired it on occasion and even allowed it to flourish from the point of extinction.
We've decreased overall human suffering to the the lowest point in all of history.
We've managed to set foot on dead worlds, and though we haven't brought life to that, yet, there's no reason to assume that in the near future we won' do so.
now can we fuck it up down the drain to the point of no return? sure. But looking back at the set of things we've overcome I think there's also reasonable hope to be considered.
So...do with that what you will