Completely agree. I think the prevalence of sequels in Hollywood underscores the point; successful content begets popular content at a higher rate than a complete unknown.
For every MCU there's a Fantastic Four standalone or a Universal Monsters Universe or a Percy Jackson or a Golden Compass or Narnia or other never-to-be-finished would-be franchises... or even just a Star Wars: Solo on the "hmm this isn't paying off after all actually even if it's not a bomb" front. And those were all existing IP, even!