I always thought race swap gender swapping roles was a cash grab

There are a lot of instances in which is can put a new spin on an old trope. Spiderman is a great example. The various swapped Spider-folks all have a unique setting and character arcs. The idea of "Spiderman" as a set of powers they all happen to share give a loose cover for a bunch of really compelling super-hero stories that could only come from a particular perspective.

If new movies can’t make new characters and stories with different races and sexes without seemingly purposefully causing controversy by replacing one race or sex with the other I’d take that as a low blow.

Its not uncommon for a writer/director to have an idea for a piece of media that's original and compelling, but get told "We have a zillion dollars for Generic IP and pocket change for Original Cinema". So the original gets adapted to IP. The lead in your spy thrill gets hot-swapped for James Bond. A gothic horror gets turned into a Dracula or Frankenstein film. The sci-fi epic becomes another entry in Star Wars cannon. The coming-of-age film gets Barbie as the lead character.

The IP is what guarantees a minimum viable audience, because its immediately recognizable. Then the screenplay itself is wrapped around the central cast. IP is just an efficient form of marketing.