Arc … of triumph?

As financial gurus say, there’s no risk without reward. I think the same is true of writing a series with an overall arc.
By “arc” I’m not thinking of something like Lord of the Rings, which is a single story in three volumes. An arc is a series of separate stories linked together by an overall thread. Each novel (or issue) can stand alone, but put together they tell an overall story of considerably greater power (if it’s done right).
The Silver Age Dr. Strange may be the first example in comics. After his initial defeat of the otherworldly tyrant Dormammu, Dr. Strange finds his mortal rival Mordo suddenly attacking with greater power than ever before (Dormammu, as we learn but Strange doesn’t for a while, is feeding him the extra energy). With Mordo’s disciples and occult scans hunting him, Strange must flee his house and his mentor and go on the run, struggling to find Mordo’s secret and strike back (spoiler: Strange wins). The individual battles are good, but taken as a whole, a tale running for 20 or so issues makes for an even stronger narrative (probably more so back in the days when that was a novelty).
For a more character focused arc, we have Jim Butcher’s Calderon series. Oh, it’s certainly full of action, sorcery and hairbreath escapes from certain death, but what makes the series as a whole more than just action is the progression of his protagonist, Tavi, from a magically talentless young man into the Emperor. Admittedly that kind of change happens in a lot of fantasy, but here we see it happening step by step, with each book.
The risk part of the equation is that a story arc places higher demands on the writer. Take Butcher’s Ghost Story, for example. As I said when I read it, it’s entertaining in itself and I’d have had almost no complaints if it had been earlier in the series. But since then, the arc of the overall series has become important, and the book didn’t deliver on that front.
Or take Lost. Here the overall arc (what is the island’s secret? How will these troubled characters work out their issues? What’s behind all the mysteries?) dominated from the first; the show was always headed toward something. And when it got there, it fell apart.
I had a similar disappointment when I finished 100 Bullets: Wilt, the final collection of the comics crime series. Over the course of the book, everyone’s plans come to fruition—Megan, Graves, Augustus Medici—and the Minutemen and the Trust finally have it out in a spectacular, gun-blazing finalé.
Spectacular … but it felt rather like sound and fury, signifying nothing. The reason for the original parting of the two groups isn’t really given enough dramatic development to be satisfying. I have no idea what Graves wanted to happen going into the final issues. I have even less idea why he recruited Dizzy. We have action, we have drama, but there’s nothing that makes me care as much as I should after 100 issues. I still love the early issues, but the overall arc just didn’t take me to the big finish.
Series don’t have to have arcs. While my Applied Science shorts spread across several years and involve multiple changes, I don’t think there’s an overall arc. But if a writer does go with an arc, it had better pay off.