Film producers will look at recent box-office and ratings successes (now informed by analytics) and decide what is worthy of development based on those findings. Obviously, audiences drive box-office and ratings successes, so yes, the audience does decide what gets made generally speaking. I'm not seeing this wealth of great new ideas being facilitated by the big streaming players. Netflix has about half-a-dozen Marvel series alone, along with popular sitcoms like Full House and One Day at a Time that are either continuations or remakes of past properties. Stranger Things was really the only big hit on there based off an original idea. On HBO, Westworld (property), Game of Thrones (property), and coming soon Watchmen (property). AMC's bread-and-butter is the Walking Dead (property). Some of Amazon Prime's big shows are Jack Ryan (property), Bosch (property). Mrs. Maisel and Sneaky Pete have been hits based off original ideas, but I don't see the occasional Stranger Things, Maisel, etc bucking the trend as an example of the industry not being heavily property driven.
Trust me, I'm intimate with the business, and you wouldn't believe some of the logic. A script based off an irrelevant newspaper article has a better chance of being made than one that isn't, even if the stories are identical. The only people that have a real chance of getting something original made are those who have heavy influence or name recognition (Tina Fey [Kimmy Schmidt], Bryan Cranston/David Shore [Sneaky Pete]), so this way you can advertise it as "From the creators of House, comes an exciting new..."
Indie isn't flourishing as well as perceived. The spirit of Sundance, TIFF, SXSW in the old days was to give exposure to complete unknowns (from directors to actors) working on shoestring budgets. Think past indie hits and award winners like Clerks, El Mariachi, Welcome to the Dollhouse, Sex, Lies, and Videotape. Now the big Sundance winners and hits feature A-listers or strong B-listers (Elijah Wood, Chloe Grace Moretz, Michael B. Jordan, Saoirse Ronan, Miles Teller) in the lead roles and have relatively large budgets. Indie is basically Hollywood-lite now.
And to be clear, my main primary gripe is the property based action movies and even shows sucking up development money that would be better (in an ideal world, obviously) put toward original ideas. Again, you try to pitch Robocop or Predator today, you'll get shown the door, as the execs explain that action movies without a property tie-in just don't hit. To boil it down, I'd like to see what a 200 million dollar martial arts film would look like that uses nothing but practical effects. Something like the Lethal Weapon 4 freeway chase scene is light years more impressive than any CGI loaded set-piece the MCU or DCU has come up with.