"… how is it that some AI's users describe their experience as a hellish ordeal, while others delight in the ways that AI is changing their lives for the better?"
The answer is contained in the concept of “centaurs” and “reverse centaurs,” found in automation theory:
https://pluralistic.net/2025/05/27/rancid-vibe-coding/#class-war
A “centaur” is a human being who is assisted by a machine (a human head on a strong and tireless body). A reverse centaur is a machine that uses a human being as its assistant (a frail and vulnerable person being puppeteered by an uncaring, relentless machine).
Also: AI is a bubble. When it bursts it will leave behind a wealth of useful tools and skilled workers, but at terrible cost.