Warner are pinning all their hopes on sequels and the returns are ever diminishing. It’s true that the years’ 4 biggest movies will all be sequels (Dune 2, Deadpool 3, Inside Out 2, Twisters) these are also not tired franchises.
The draw of the MCU was that whilst the films are all interconnected it tended to be through more ‘nod and wink’ scenes for fans; you could watch only your favourite characters and not lose anything. (They forgot this and decided numerous TV projects were the answer)
Audiences do not want to watch movies that require homework or investment. It’s why Kevin Costner’s Horizon flopped: you release a movie with a ‘Part 1’ in the title and it immediately turns everyone off via potential commitments.
There is also an unspoken truth in Hollywood: TV finally killed movies. The days of the breezy 90m blockbuster are long gone. They want to tell deep stories over 2.5h that would be better suited to TV serials.
If they want to turn cinema around it’s actually pretty easy: throw less money at a few more risky original projects. But crucially insist on a 105m max runtime and aim the movies at families.