Why did Flaubert finish is writing career with the tale Herodias?

It's hard to figure Flaubert's fascination with the "near East" - if my memory serves me well I think he traveled in Egypt in his youth and kept some pretty explicit diaries that were published posthumously? - except maybe it was a style of the time, the way India was for Americans in the 70s and maybe Prague and Budapest today? but Flaubert was the greatest naturalist writer, and looking back on his work it's obvious that we read Flaubert still a century + after his death for 2 works: Mme Bovary and A Sentimental Education, and not for Salammbo, The Temptation of Saint Someone (can't even remember the title), Bevouard and Pecuchet, if I have these names correct - so why, in his final work, 3 Tales, does he end w/ this rather boring and impenetrable piece about Herod and the crucifixion, all told from Herod's POV, more or less, as he tries to form an alliance with the Roman consuls, worries about uprisings of the Jews,  holds John the Baptist in captivity, pushes back against the militarism of his wife, Herodias - the eponymous Herodias, in fact, though the story doesn't seem to be hers. There's obviously drama to be made of of these events, and others have done so, in numerous art forms - The St. Matthew Passion, the Wakefield Mystery Plays, and how many paintings in the Lourvre? - but Flaubert brings to little of his great style to his tale, it has no inherent drama - all of its dramatic energy comes from without, you might say, from the pre-knowledge we bring to the tale and not the knowledge and insight it offers to us - and it's a mishmash of place names and names of various generals and leaders - perhaps he's trying for an epic effect as in the Iliad listing of armies and ships?, but it all serves to make the story incredibly difficult to follow.