MMA is highly advantageous for grappling styles. in a street fight, you can't afford to go to the ground, because while you're going for that arm bar his buddies are coming to kick you. striking arts are still king on the street.

as for kungfu/karate vs MMA, it really doesn't matter. it's not the martial art. it's the fighter.

if you're taking a kungfu/karate guy that mainly focuses on forms and katas, of course they are going to get their ass handed to them.

if you're taking TKD guy who only competes in tournaments where sparring is a point system, of course they are going to get their asses handed to them.

if you taking anyone who even wears pads during sparring, of course they're gonna get their asses handed to them.

anyways, if anyone's seen the Tito Ortiz vs Chuck Liddell, you just need to know a little bit of takedown defense and the grapplers will have a bitch of a time trying to take you down.