Studios get about 55% of the domestic gross, 40% of the overseas gross, and 25% of China's gross.
For franchises, you also have to consider trends. Covenant wasn't a bomb, but it made just over half of what Prometheus did. Do they make a third film and risk another 40% drop? Covenant wasnt exactly well received.
Unless someone wants to make a $50M Alien film, it might be best to let the franchise lie for a decade or so.