Skips all the detail and pivots to what I think as the crux of the matter.

I see both GRRM and Frank Herbert as two people who distrust the creations of messiahs / anointed ones as part of their work. Sometimes messiahs improve the status quo, sometimes they make it far worse. But literally the power to destroy the status quo power system with their army, or their religious revolution, or their dragons, or dozens of other sources of power...

That power is inherently unchecked for it was forged in a crucible and all the “circuit breakers” that limit that power is gone. Thus those people are more likely to be tyrants, more likely to focus on domination and the urge to not be dominated ever again, and thus they will eliminate all people who challenge their authority in a top down fashion, while simultaneously they may accidentally break aspects of the state and bureaucracy that reduce the chance of famine and disease which in turn kills the small folks in a way different than the upper classes die due to the sword.

I think Dune influenced GRRM more than JRR Tolkien’s The Lord of the Rings.