I’ll go with the low-hanging fruit: Mein Kampf. I’ve read it, cover to cover. As a piece of propaganda, it’s good. As an example of good writing? Absolutely not (though I will admit I have only read it in translation). Oh, and the whole fascist, racist, and generally shitty worldview of the author that he infuses into the text. And the fact that the author is literally Hitler. You 5-star that book? You’re a Nazi. Period. And as a Jewish person, I don’t look too kindly on them.
I first read it in highschool and even then I could already register how thin it was, but at that point I was already reading writers like Terry Patchett, Neil Gaiman, and Ursula K. Le Guin so I guess I had been introduced to more clever writing. That semester we also read ‘The Solitaire Mystery’ by Jostein Gaarder and IMO that was a much stronger introduction to some of the same philosophical themes as The Alchemist.