See, this is a fundamentally unreasonable demand, because it ignores one huge factor: the incumbent advantage. Established characters and stories will *always* have an advantage over new ones, because they got their first, establishing their presence in the cultural milieu. Fundamentally, the market favors established properties, because people would rather spend their money on something they have reason to believe they will like, rather than on something they have no such assurance. That is why sequels and reboots and spinoffs are so popular, even as people complain about an alleged problem with innovation. Yes, you can find individual people who are exceptions, who eagerly and aggressively experiment. When talking 9 digit movie budgets, these people are too small a segment to matter.
Trying to take an entirely new character, and bootstrap them up to even an approximation of the cultural relevance of 50+ year old ( nigh exclusively white male ) characters, is *really really hard*. And simply saying "people should support new characters" is not a plan, its not even an outline. At best it happens by pure chance, where a new character is in exactly the right place at the right time to catch on with the general audience.