TBh, I think part of the issue is that even in terms of commissioning projects, they aren't just looking for people with great stories. They just want a lot of them.
I mean - if they want to do a story set in a place like Africa, or Japan, or whatever, there are some great options, both from historical periods or modern stories. These will be very expensive I would think, and possibly finding enough actors to populate said film might be tricky in some cases. It can be done obviously but it's not as simple as putting out a pretty open casting call for something set in Europe.
But it's not surprising that in a country like the UK, or France, or Hong Kong, a majority of the films and TV are set in the UK, France, or Hong Kong, including historical dramas, and the actors used will reflect that.
Right now it feels like there is a desire to keep up a rate of historical productions set in far away places that might not be very realistic or reflective of the population. Like - we wouldn't expect that, would we, from the television industry in Korea, or Nairobi? I know a lot of people who watch Korean TV now, and you know, the people on the shows are all Korean. There seems to be zero push for "representation", even though there are other people from away living in Korea.
More modern settings are much easier, where you have stories set in the UK that reflect the origins of groups that have come more recently, and I think these emerge more naturally. Which is what we should be looking for, good stories coming from good writers.