As I understand, he left penning down his philosophical thoughts till a rather late age and wrote the Critique of Pure Reason at a point where he was worried he wouldn’t remember it all and consequently it was done under a lot of haste.

Now I want to really read his writings

Pretty incontrovertial. Most of our surviving writings “by Aristotle” are actually lecture notes from his students rewritten later. So it’s got a lot of the hallmarks of being written by committee and coming across as being very dry.

Compare this to Plato, whose writings were actually pretty entertaining even as pure fiction. He’s full of side stories, lurid metaphors, and funny turns of phrase.

I've read Aristotle in two classes, and both times the professors have commented on the writing style to prepare us. In an ancient philosophy class, Aristotle still stood out as densest and dryest.

I'll second that. After reading the history of sexuality by Foucault in college, I remember coming to the frustrated realization that the point of this jargony disaster of a book could have been made in a couple pages, possibly less. In essence, it says that to be free in one's sexuality, putting words on things which may feel rebellious is actually just trying to define practices and feelings that don't need this to exist. So, talking about sex is actually not rebellious and freeing in any way but rather normative and constraining. This was actually an interesting point to consider as a young adult, and I am glad I encountered this when I did, but a whole book for this is beyond overkill.

Other than the structuring, moving from topic to topic without explanation (e.g. Categories), I actually agree. Maybe terrible isn't the right word. He's a lot more like reading modern math.