jamie could've been good if he was drinking 4loko or monster energy or something that made sense for his age range, it feels like there's a huge personality and design clash with his drunken fist style? also he's the worst chinese rushdown character to date in terms of how usable he is, barring maybe lee (lol)
This complaint is so out there I don't even understand what your issue is with the old school drunken master flask + bboy style combination. It's a deliberate contrast to make the character interesting. You have an old school trope combined with modern style.
Like do you honestly feel he'd be better if he was sipping from a 4loko (dated) or like a white claw, strong zero or monster energy can or something instead of the flask? the whole point is my boy being out there in the dunks and his versace tracksuit with the grammas flask. the tension between these elements is what gives the character personality.
It also works in contrast with luke, who is a fairly straight laced (solider, martial arts coach) character with a modern fighting style. as opposed to jamie who is a wild character with a traditional fighting style.
The traditional kung fu + modern style thing isn't even new to street fighter- Yun & Yang had the same theming with the old school martial arts + skateboarding/rollerblading.
Don't agree the personality clashes with his design either, his personality is pretty much a copy paste of Jackie Chan in drunken master 2 - braggadocious but ultimately with a good heart. Having someone be in touch with their roots alongside being hip isn't exactly weird. I think conceptually he's a great character.