It's also worth pointing out that long-term, comics-style stagnation seems to be increased by the simple fact of having more than one distinct writer or writing team over time. Usually, when a single writer makes a major change, they intend for it to stick, because it fills some purpose in the overall story. But writers don't respect each others' work. They look at a story written by someone else, a finished, working assemblage of many pieces, and just see the pieces, like autists. Like junkyard scavengers. They just want to steal what they can use and don't care about how it fit into the previous whole. Character you want to use dead? Just bring him back. Character got development, and you wanted the old version back? Just undo it. Of course, for comics you pretty much have to have this attitude, because bad writers happen and good characters and other setting elements get gratuitously trashed all the time by Hamhands McDipshit for emotion that the stupid hack was too incompetent to earn legitimately (or by editorial mandate to grab a temporary sales spike).
Having multiple writers in sequence is also a great way to have important details forgotten or just gratuitously changed because the new guy didn't like them or didn't understand their intended purpose and introduce tons of continuity problems.
Of course, franchises like comics that are intended to go forever (or at least until the money runs out) have to have multiple writers over time, as old writers die/quit/get fired/get bored and want to do something else, so that's another way in which never-ending franchises sabotage themselves.
Years ago, I eventually reached the conclusion that all such long-running, multiple sequential author franchises were destined to be unsatisfying to me, and stopped caring about all of them. I haven't regretted it since.