I completely respect the point of your post. It is easy to cast actors and actresses of color. Movie companies are letting people down and not looking deeply if they want to claim they can’t find good actors and actresses of color. Your post is, however, mostly incorrect.
I assume by the wording you think Lionsgate is not a part of Hollywood. This is incorrect. Lionsgate is both physically and culturally a part of Hollywood. They make big budget block busters, with headquarters in SoCal, and they have a studio in Hollywood. They are very much a part of Hollywood. Your whole post doesn’t make sense if Lionsgate isn’t a part of Hollywood. The companies in Hollywood don’t give two shits about other companies because they don’t gross nearly as much as movies that come out of Hollywood usually do. Hollywood would look at Power Rangers and essentially say, “well, it hasn’t grossed it’s production budget, so why would we want to model our movies like they did that one?” Hollywood looks at movies like Civil War, which grossed nearly 5 times its 250,000,000 dollar production budget. Civil War used name, white actors. If Lionsgate is not a part of Hollywood, it doesn’t matter to Hollywood.
On the other hand, if you’re saying Lionsgate is part of Hollywood (which it is), then the validity of your point crumbles because of the example you are using. Power Rangers was, objectively, a bad movie. The writing was choppy, the plot was weak, and the acting was mediocre at best. Special effects were relatively rudimentary. Even the positive reviews of the movie (of which I read dozens) said that they liked it because it invoked nostalgia, but it was a bad movie.
To actually prove your point (which, again, I agree with), you’d want to use a movie like Moonlight. Moonlight was not produced in Hollywood, the acting (even by the small children) was phenomenal, and it was immensely successful in awards shows and was financially successful (it made ¼ of what Power Rangers has made, but you have to keep in mind that it has a niche audience and the release was limited). Power Rangers is not the movie to use to prove a point about casting actors of color and how Hollywood ignores actors of color.