Ryu is the most popular fighting character of all time. He’s also the reason that 1-on-1 fighting games are popular. You didn’t need to know Street Fighter to recognize him saying Hadouken. Without him, it’s doubtful that Tekken and Mortal Kombat would get made. This is why his outing in live-action movies has been disappointing.
In the first movie, Ryu wasn’t what people expected. He wasn’t a fighter looking to better himself. Ryu (along with Ken Masters) was a con artist. No one wanted to see that. When he finally got a chance to fight, lackluster is putting it nicely. He wasn’t even in the next live-action movie. Ryu was mentioned at the end and fans knew that they’d never see him because there’s no way The Legend of Chun-Li was getting a sequel.
Ryu doesn’t have to be the star of the movie. He may not be the character that keeps the non-video game fans interested. Nevertheless, he needs to be an important part of the film. At the very least, he should have a couple of fights where he looks dominant. If not, this will become the third missed opportunity to use Ryu properly.