Sort of switching gears here…
Most people would agree that Canto Bight was ultimately superfluous to the story in TLJ. But if it were developed just a bit more, it could be the most interesting commentary on the Star Wars galaxy and meta-commentary on the Star Wars universe that has yet appeared in the movies.
All of the questions about the feasibility of Starkiller and the First Order navy could be answered if it were established that there are certain powerful businesses in the Star Wars galaxy purely interested in constant war for the profit they create. The clues are all there in the sequels, from Jakku to Starkiller to Canto Bight and beyond.
I realize that this is probably the point of Canto Bight, but as it is it feels like a bit of simplistic moralizing instead of a revelation. To make it work I think there would need to be more emphasis on a single huge company or constellation of companies which are basically the puppet-masters in the galaxy.