Did you watch the videos I sent? The question you raised is which is the better fighting art for street fighting? Then, you added the question on why there are no MMA Kung Fu fighters. I answered both. The videos you just posted have nothing to do with your questions. They are just sparring videos.
The videos gave the answer to both. First, while the more traditional arts have kata's, forms and some really neat expressive techniques, as explained in the videos, we also teach the techniques that are affective. I wrote a book called The Positive vs. Negative and Zero Rule for Self Defense. (PNZ) I started it decades ago. I just have to take a bunch of pictures and then publish it. In it, it's about those simple moves that give the upper hand. Wing Chung teaches to press forward. I call that the Positive Motion. Moving back is called the Negative Motion which leads to negative results. Standing still and fighting is the Zero Motion in which the stronger and/or bigger of the two fighters wins. However, with the Positive, when an attack is straight line towards the victim, the Positive Motion is 45 degrees stepping forward with the left or right foot. Parry both arms to cover both punch or kick. The back leg raises up and you kick the knee of the attacker from the side. Takes only 7 pounds of pressure to tear the tendons and ligaments. One quick motion for all of it. You can follow the kick with punches or more kicks. But, I generally teach to step out if the kick is successful and leave. For circular attacks with a stick or roundhouse kick, move directly at the opponent with a punching combination and throw a kick into the groin. In a street fight, I'd suggest striking the eyes with your two fingers. Always works. Especially if the victim is a woman or child. Then, kick the groin. The flying kicks and fluffy stuff are mostly for show. Very experienced fighters like myself can use them in street fights and get away with them.
As for grab holds, the first thing is to move into the attacker reversing the hold or control. Then quickly striking the soft tissues mostly followed by kicking the groin if possible. As an example, a simple double lapel grab attack. Step towards the attacker bending your knees. As you do this, with your hands, push the attacker's elbows in and down pulling the attacker close to you. Now, you have them in a hold. The step, hands to elbows and pulling is done in one motion. Then, put your palms together and together thrust the palms into the jaw of the attacker as hard as you can. Then, raise your knee up and extend your foot into his groin. Break away in a 180 degree turn with the kicking leg and leave. I call it Dragon's Mouth. That's the move my student did to the much bigger senior who wanted to throw him into a trash can on Senior Court. The important thing is not to get all tangled up with the attacker because if there is a second attacker, they will hit you from behind. I teach to take care of the attacker quickly, turn and step out so you can see if there is another attacker. Turn bac to make sure the attacker is down and then get out of there. Very simple. I have 12 simple grab hold defenses that I teach. Within each one, there are several moves, kicks, strikes or punches they learn while defending themselves. In about a month, they know these 12. But, they also know about 100 individual strikes, kicks and foot work techniques. This is what I call Whole to Part learning. Same with the non-grab attack defenses using the PNZ Rule. I also don't teach punches and kicks individually. I have sets of kicks they learn so that in one set, there may be 4 or different kicks and punches. That way, they learn how to do them but in a sequence. Most Kung Fu systems do the same thing. So does Kenpo Karate which is a Korean style of actually Kung Fu. They even call their teachers Sifu instead of Sensi.
Now, as far as why no Kung Fu people are doing MMA question. That was answered in the videos. But, since you didn't watch because you think you know everything, the reason is quite simple. The techniques are mostly not allowed in MMA. Can't kick to the groin, poke the eyes out and many other techniques. No heart stopping strikes to the chest and stuff like that. Kung Fu, Wing Chun and arts like that can't be used in MMA.