Disagree vehemently with your portrayal of this aspect. You even contradict yourself, pointing at sine waves (clusters) of bad RNG as the issue - while dogmatically brushing off the optional loaded-dice (who breaks clusters) as a solution..
Because it IS a poor solution.
The ideal design around a system that is perceived as "way to reliant on RNG and too unpredictable on its outcomes" is to tweak rules or the scenarios offered to give better predictability. Not to cheat behind the curtain lying to the player about the dice rolls.
A classic example is a situation where a failure doesn't force a re-roll or reload of a previous save game, but creates an alternate and equally interesting outcome.
Re-read the entirety of my post please, because you obviously didn't read more than the opening paragraph. This is one of MANY "solutions", one of MANY "tweaks".
Past these many efforts, more than dealing with "way too unpredictable RNG and outcomes", we are dealing with the catering to the lowest common denominator of obsessive compulsive behavior coupled with a strong intolerance of any deviation from perceived perfection. "Snowflaky entitlement" issues if you will.
Let's take the situation with the dying illithid at the crash site near the Ravaged Beach to illustrate my point on their "layered RNG-system" alone:
You can kill the illithid from afar (knowing its mental powers and being informed the people are thralls). Opting to not do so and approaching, you have a DC 15 persuasion check to convince thralls to stand down. Fight vs. thrall commences with failure. Mid-fight, you get another DC 10 wisdom check vs. mind influences of the illithid. Success leads to thralls breaking free. You can now again kill the illithid (definitely knowing how dangerous it can be), or you can approach it. You get a DC 10 intelligence to (foolishly) lock minds with the illithid, if you "succeed" you get another DC 10 wisdom check to avoid being killed. Even when killed, you are rewarded with an exciting battle (and, should you win, more XP than otherwise I believe), at the cost of using one scroll of revivify.
