Chauvin's trial was dominated by expert witnesses giving dubious opinions of questionable relevance.
Rittenhouse testified for his defense, and explained why he did what he did.
Update: There was another thing Rittenhouse's testimony revealed. He is someone who may be perceived as easily bullied.
Rittenhouse avoided conflict thoughout the riots, refused to argue with anyone, offered to help people, and generally seemed weak. It seems quite likely that his attackers assumed that he is someone who will not fight back. That is, they could take away his gun and he will not shoot.
It would have been irresponsible of him not to shoot.
All of the charges carry long prison terms, except for one misdemeanor gun possession charge. I wonder if that could withstand a Second Amendment challenge. At age 17, he could have been in the army, or hunting, or doing target practice, and apparently Wisconsin law allows that. But not self-defense? The jury instructions on this point have not been announced yet.
While a lot of the Left is hoping for a guilty verdict, I have yet to hear an explanation of what Rittenhouse should have done. Run faster? Allow hostiles to take his gun? Fire warning shots into the air?
Arguably he violated curfew, but he was not charged with that. He had as much right to be there as anyone else. He only shot when he had to shoot, and he did not hit any innocent bystanders.