If you belief MMA fights are the same as real street fight then you are wrong. All big MMA promotion companies like UCF, Bellator FC and ONE Championship are operating nowadays under strict rules. These rules are making a huge difference between a controlled MMA fight and a real street fight. The most famous rulesets are Unified Rules of MMA (UFC, Bellator FC) and Global MMA Rule Set (ONE Championship).
Those rules are normally defining the prohibited techniques, the protection gear (gloves, mouthguard, protective cup), the rounds (number, length), the judging criteria, the weight classes, …
Prohibited techniques: Groin attacks, Biting, Fish hooking, Eye gouging, Hair pulling, Manipulation of toes or fingers, Throat grabing or striking, Striking against of the back of the head or the spine, Knees or kicks to the head on grounded opponent, Headbutts, Attacking during a break, Grabbing the opponents gloves or shorts, Downward pointing elbow strikes (Unified Rules of MMA, not complete)
In a street fight your opponent will maby use weapons (Knuckleduster, Stick, Knife, Gun) against you. He may also get help by some friends who can attack you from behind and use waepons aswell. They possibly don’t stop when you have lost consciousness and will kill in a rage.