I think this phenomena has passed. Certainly the book sales don’t show that this model offers much in terms of sales boosts. Too many books now, and once you let go of some of the continuity you quickly graduate to not caring at all. That plus the advent of digital means there’s not that same soap opera element driving sales. You can miss out on an event or a series and just pick up where you left off.
Clearly the evergreen trade model is driven by elseworld and standalone books. The in continuity series barely sell at all, have little presence in the bookstores and are quickly forgotten. So something is being lost.
If you look at what’s worked best for Marvel over the last few years it’s Vision, Hawkeye, Squirrel Girl, Ms Marvel, Spider Gwen, Old man Logan, Star Wars - they’re all continuity free somewhat and let the creators go a little wild. The in-continuity stuff is getting hammered by a dissatisfied audience.
I think Batman leads the way here. Batman isn’t a remarkable character, but after all these years he’s still the most popular comics creation. And I think it’s because creators can do what they want with him. So they can put their skill and talent in and give us a Killing Joke or Dark Knight Returns or Batman Inc or Year One or Gotham by Gaslight or Arkham Asylum or Hush or Dark Mirror or Court of Owls. No-one cares which order to read those books, no-one cares if the stories count or not. They’re just stories, and people can understand if there’s inconsistencies.
I think Marvel probably has 30 properties that could exist this way. Cap, Stark, Hulk, Widow, Spidey, Iron Fist, Daredevil, Punisher, Ghost Rider, FF, Guardians, Thor, Ant Man, Strange, Captain Marvel, Deadpool, X Men, X Force, Deadpool, Wolverine, Black Panther, Ms Marvel, Squirrel Girl, Gwenpool, Miles Morales, Luke Cage, Thanos, Inhuman, Nova, Defenders. 10 of those can support 2 books at once. Add in 10 more series for minor properties and you’re in good shape. All could carry their own line of stand alone books and get close to a Batman-esque presence. If free of the limitations of continuity and hobbled creators.