Check how many attacks right-wing groups and Neo-Nazis in particular have done in USA in the last 10 years. Then compare that to attacks against Neo-Nazis or right-wing groups in general to see that although some fash has been bashed and there was that one shooter who attacked congress member... There's just practically no organized terrorism from any group that could be seen as the left-wing equivalent of Neo-Nazis.
You got a few people who call themselves ANTIFA hit some heads but even from those we have as many false flag attacks as real ones. (Like that one guy who stabbed himself and tried to frame ANTIFA but admitted it eventually. OR those FB pages for supposed ANTIFA attacks or protests against Confederate statues that were right-wing trolls trying to encourage leftists to commit terrorism. All of those failed btw.)
And in the protests like the "Unite the right" rally we saw that the counter-protestors consciously tried to prevent any violence. They in fact organized people to keep an eye on fellow counter-protestors to get in between of any imminent conflicts because they didn't want people to say that they attacked Nazis.
So you've got couple dozen ANTIFA wannabes who are Ancaps or Anarchists and want to beat up Nazis, and tens of thousands of peaceful people who just don't like Nazis and are willing to march agaisnt them. And some more random people who want to violently oppose Nazis but aren't part of any groups.
Meanwhile on the Nazi side of the equation... You have organizations that are openly violent and admit that they support a genocide. You have people bringing guns, armour and melee weapons to protests AND using all of those. Guy who has a high rank in one of the KKK offshoots called a counter-protestor a nigger and tried to shoot him. (His gun failed to fire and when he fiddled with it, it went off and hit the ground. He is now going to court for firing a gun near a church. This despite police being few meters away from him when he fired the gun. They ignored this attempted homicide until the video went viral.) There was the guy who drove over people. That was not an accident. Not an accident by the terrorist and not an accident in that he just randomly thought of using a car. Right-wing web pages have been encouraging people to run over protesters for a year at least. They have been drooling over themselves at the thought of running over people who protest against Nazis and telling each other to do it.
The violence on the "two sides" is not comparable and neither is the encouragement for violence.
