No, are useles, I hve fighted against black belt in karate and they are awful.
The moves are stiff, and is and they mark their movements (so is pretty easy to know what they are going to do). Also when they hit you they stop (and when they try to keep hitting you, they become a mess) and when you hit them they think that one hit and there is not going to be other, so they low their guards.
I don't see why you think Karate is useless. If you need proof so bad, here's a video of two guys fighting, one using karate and the other kung fu
and I don't think people here think it's useless. People have said that they didn't like it when they trained in it, which is fine. That doesn't mean its a bad martial art.
Now if all you're going to do is bash karate, you can go post somewhere else. We don't need you trolling this thread; I would rather have a decent discussion rather than try to prove shit to you.
The kung fu guys in previous video only trained to use their fists, which is why they got their butts kicked since they weren't bold enough to close the distance into their own effective range. I also suspect it's against karate etiquette to rush in and bash the opponent repeatedly with fist techniques. Remember, those guys were performing on TV.
Conversely, (never mind the ethnicities haha)
And THAT, my friends, is why you never ever perform a roundhouse high kick in a real fight.