only times you're gonna charge with chun li is mid combo or against a character that you can out zone, other than that you don't have to worry too much about it
it definitely wont win any fireball wars (unless you meter burn it) , but it's not completely useless. it's good for approaches since it's slow and once you throw it out you can just walk behind it
then depending on how your opponent reacts to the fireball, you can react accordingly to do damage. they block it standing, go for a low, they block it crouching, go for overhead, they jump, go for air-to-air