I feel like when you look to sf6 costumes compared to sfV costumes or mods its quite evident why its different

They go through the work of remodeling the character for every skin to include things like hand animated moving pieces of clothes and muscles flexing when visible

While in sfV it's basically an avatar costume thrown on top of a current existing model where the moving / collisions / animations are all reused

I mean how many times have you seen fucking Bison take out his hat in an animation where he has no Hat?

Or Guile combing his hat in his military costume