I wasn't trying to suggest that there's a "rule" that studios have to follow...I was merely expressing my opinion, based on my observations of the patterns typical of super-hero movie franchises. You seem to see the seven Batman movies since 1989 as a continuous series with small interruptions, a la Bond.
No, I don't. I'm not talking about what's been done in the past, but questioning the idea that some kind of rest was necessary in the present/future. Whether or not there was a long enough rest between Schumacher and Nolan had no bearing on the success of the Nolan films. The Nolan films worked because their makers did a good job. They would've worked just as well if they'd been made years earlier.
Conventional wisdom is that where super-hero movies get sequels at all, they tend to make 3 or 4 films, and fans usually don't like 3 or 4 nearly as much as the first two.
"Conventional wisdom" means what's widely believed, not necessarily what's actually true. And human beings love to project patterns where none exist. Film franchises run as long as they make a profit. The only numbers that are determinative are the box office returns.
And really, there aren't enough long-running superhero film series to allow drawing any statistically meaningful conclusions about their patterns.
Are Batman and Spider-Man examples of a new trend of super-hero franchises that keep churning out movies at a fairly regular pace into perpetuity, occasionally undergoing creative reinventions but never fully stopping?
I never said they would be. The alternative to one extreme is not the opposite extreme. Most truths lie in the middle ground. I'm only saying that there's no reason to think there's a
requirement for a long rest. Sometimes a series goes fallow for a long time, but only because it's had enough failures that there's no interest in a new one. If, as in the case of Spidey or Batman, a series is brought to an end on a fairly high note while audiences still have a generally positive view of it, there's no reason why a reboot couldn't succeed just a few years later. And sometimes a series that did run out of steam due to disappointing box office, like
Star Trek, can nonetheless be successfully relaunched without too long a rest. (There were seven years between consecutive feature films, but only four between consecutive productions inclusive of TV and features.)
The point I'm making is that it's not about some kind of overall cosmic pattern that makes things happen a certain way. It's about the individual circumstances and performance of each individual movie series. A series will last as long as it produces successful movies. No, there's no guarantee that it will continue to do so "forever," but neither is there a guarantee that it will
stop doing so after some arbitrarily preset number of films, or that there needs to be some minimum interval before it can start up again.