A franchise that runs for decades eventually rearranges its own history, whether by reboot, reset or quiet contradiction. The pressure that produces this is arithmetic rather than creative restlessness.
Continuity accumulates faster than audiences do
Every installment adds facts that later installments must respect. After enough of them, the set of constraints becomes larger than any writer can hold or any newcomer can learn.
The effect compounds across media. A character's history may be spread over films, series, comics and games, each adding details the others are expected to honor.
Eventually the backstory becomes a barrier. A prospective new fan is told, correctly, that enjoying the current entry requires substantial prior investment.
New audiences are worth more than old ones
Existing fans are already reached and largely already converted. Growth has to come from people who have never engaged with the property.
Those people need an entry point that does not presuppose knowledge, which is precisely what a dense continuity cannot provide.
Rights holders therefore periodically prioritize accessibility over consistency, accepting complaints from a committed audience in exchange for a viable entry point.
Resets come in several forms
The cleanest is a full reboot that discards prior events and starts again, which is simple to explain but discards affection built over years.
Softer options include a continuity that branches, a story set far enough before or after that prior events do not intrude, or a selective retention that quietly ignores some entries.
Branching versions have become common because they preserve older material as valid while freeing new work from it, which is a commercially convenient compromise.
Contradictions are managed rather than avoided
Large franchises employ people whose job is tracking established facts and flagging conflicts before publication or release.
Even so, conflicts occur, and the usual response is to leave them unaddressed rather than to invent an explanation that creates further constraints.
Explanations have a cost: each one becomes another fact that future work must respect. Silence is often the cheaper option.
Aging characters force the issue eventually
Characters with fixed ages who have lived through decades of published events create arithmetic problems that no amount of careful writing resolves.
Some properties handle this with a sliding present in which the same span of personal history keeps shifting forward relative to the real world.
Others simply stop counting, which is why a franchise can reference a modern setting while treating events written generations ago as recent. The inconsistency is the least costly available option.