You’ve never seen him fight, so how can you say that? I have seen him fight, and I’m a trained fighter, and he scared the hell out of me.
A real street fighter is someone who gets in a lot of street fights, and who is mean enough and talented enough to win most of them. They’re guys with experience in street fighting. But mostly, they’re tough and mean. Hitting them doesn’t startle or frighten them, it makes them angry. They don’t fight ‘fair’. They don’t face off with you and dance around looking to trade punches - they push you over a chair without warning then kick you in the face while you’re on the ground.
Most people have never seen a real street fight, let alone been in one. They may have had schoolyard fights in grade school, and maybe been in some shoving matches that ended when someone got punched and the fun went out of it. I’ve seen several people sent to the hospital from bar fights. I saw one person get his back broken and turned into a paraplegic.
Here’s the difference between a ‘real’ street fighter and someone who’s just mad and wants to fight you: The guy who’s mad will ask you to get out your car, then he’ll push you around and stick his face in yours and goad you into fighting. The real street fighter will tell you to get out of the car, and then while you’re getting out he’ll kick the door into your head or foot and start punching you in the face.
A trained boxer will do fine against an untrained, unprepared guy who’s not really a fighter but who is either enraged enough or goaded on enough to get into a fight with him. A trained boxer may or may not do well in a real street fight, because if he’s up against a real streetfighter he’s probably not going to get a chance to even swing at him.
If I was going to rank a single trait as being most likely to be decisive in determining a street fight, it would be ‘meanness’. Most people are civilized, and are constrained by that. Even a boxer who’s used to being punched in the ring may lose his focus when he’s just chatting with a girl and suddenly gets punched in the side of the head and finds himself on the ground with a screaming, spitting maniac flailing on him. It’s disconcerting, to say the least.
The second most single thing determining a real bar fight is: whoever throws the first punch. Getting sucker punched will startle anyone, and if the opponent is really mean, that momentary startle is all it will take to give him time to swarm all over you.
As for boxers who have beat up street fighters on video or whatever, bear in mind that a lot of people who go into professional boxing or serious martial arts are also tough street fighters with plenty of experience. In that case, the boxing just makes them tougher and harder hitting. They would definitely have an advantage.