I don’t make movies but I have been working nights and weekends for nine months on a robot design [1] that is CC0 licensed, which means no copyright public domain.
The work can be a reward on its own, and work done by this kind of passion has a character very different from a massively for profit movie. Personally I’d enjoy the art more if we had no copyright. Then only those passionate about the art would make it, and people would fund what they enjoy. I’d vastly prefer that system.
In other words, I believe artists and drug manufacturers alike would still find ways to fund important work even without intellectual property law or secrecy of information.
I don't agree.
As movie equipment gets cheaper and more widespread, movies become less and less expensive to make. Of course the more special effects, post production, high-rate actors and actresses, etc., the higher the cost. But a lot of the barriers getting smaller over time. And I'm not an expert, but I'm willing to bet there's plenty of fat to potentially be trimmed from Hollywood budgets.
An open license might contain a non-commercial restriction. It could hypothetically be given an open license at some point after its initial, non-open release. For example, not a movie, but Id software has released the code for Doom and Quake several years after their release.
Additionally piracy will always take a piece out of your potential customer base.
Let's look at how movies make money now.
Ticket sales: Showing the movie first in theaters. The great majority of ticket sales happen around the time the movie is initially released. There's no reason a movie couldn't be given a more liberal license after this period. Ticket sales have also been dropping, probably because streaming has become so ubiquitous, but it hasn't stopped. Many people enjoy the huge screen, popcorn/etc. experience, which can't exactly be "distributed" in the same way as a video file.
DVD/Blu-ray sales: Again, with a non-commercial open license, there's no reason they couldn't continue to make and sell these. Bootlegs would be easier to obtain (and just as infringing as they currently are), but they'd be just as easy to pirate as they currently are too.
Streaming: The biggest feature that drives streaming subscriptions is convenience. Being able to watch a program just about anywhere, on most or all of your devices, in high quality(1080p, 4K, and probably even higher in the future). A copy distributed under a non-commercial license would mean you couldn't charge to stream the content, so you'd be stuck with a bill for the bandwidth. Studios could strike separate commercial license deals (like they already do) for streaming distribution. You could use something like bittorrent (in fact this already exists, streaming movies via torrent), but you're not necessarily guaranteed quality.
Merchandise: I'm sure I'm sounding like a broken record now, but a non-commercial license could prevent sales for merchandise. Also you'd still have all of your trademark rights. Plus most merchandise is pretty cheap to produce at scale,
I could be wrong, but my impression is that people are generally willing to pay for things - as long as they feel like it's a fair deal. They don't care about licenses, deals with streaming services, reasons behind strange restrictions on distribution, etc. They want to watch movies without jumping through hoops. There's plenty of money to be made on merchandise, experience (theaters), and high quality for-profit distribution.
Additionally content (subject to jurisdiction) eventually becomes public domain anyways, the most open of licenses. :)