He did. He went through a trial where he was found "not guilty". You remember what that means, don't you? It means he's not guilty of murder after going through all the evidence of the incident and due deliberations by a jury of his peers. That means that any attempt to make him "pay" any more is just a personal vendetta on your part and nothing about justice. Since he's not a murderer, what do you want him to pay for, cleaning up graffiti, putting out a fire? The cad.16 years from now, Rittenhouse will be on a skid row somewhere, or in a trailer park, with a "where are they now" segment.
Rosenbaum went to jail for what he did. He then got time tacked on to his sentence because his mental illness didn't get better in prison. So he paid for what he did.
Rittenhouse needs to pay for what he did, as well.
Face it, you don't care about justice, you just want revenge on a kid who got in the way of some rioters.