I’m OK with Thucydides. This is not because it seems easy. Instead it’s due to comparison with other unadapted Greek that I have tried. It’s all difficult to me. I have to look up many words, consult translations, and study grammar topics.
I haven’t learned enough Greek yet for me to perceive the comparative difficulty of Thucydides.
I believe I have learned why Thucydides is praised by the historians.
Here are some typical features that may appeal to the historical tribe.
Thucydides observes a distinction between the narrative form, and the dissertative (or critical ) form, which I learned about from Hayden White. When he narrates, the story rolls along, seeming almost to “tell itself” (White’s expression). But, now and then he pauses, and addresses the reader in his own voice to, for example, distinguish between justifications given by rulers for war, and what he considers the real cause. For the reader, he explains how he uses speeches that he has constructed himself.
He gently mocks the man in the street for believing implausible rumors. He explains that fanciful or legendary explanations will not be part of his story. He brags a little about how hard he has worked in his researches. (And I do marvel at his work.)