If it does well in China it could add $50 to $100 million or more to the movie's box office.
More like $100 to $200 million or more. The number of movie theaters in China has exploded in the past decade.
Maybe China also returns the lowest amount of box office to the studio (25%iirc). , USA one of the highest.
Also, 25% of 100s of millions is still lots of money.
The studios care about the (real) bottom line. If success in China is a mere 10% boost to box office revenue, that can easily turn films that lose money into films that make money.