It is not that simple because the Russian state interfered as well and incited violence and rioting and a lot of these people are quite simple?
And of course, we can just say any real life violence is a crime, of course they are, but sentencing is meant to take into account the whole picture. The simplicity of the person, the online grooming they may have experienced, the Covid closures, their insularity, their poverty.
The hard underlying fact remains that we as a society are failing are young and they are exposed to the violence online and we are not policing it and social media giants are not taking responsibility. Online violence has to be banned and responsibility has to be taken and laws need to become really strict, even regarding viewing of content.
As for the algorithms - again businesses profit immensely but at what cost to society.
We are always one step behind all of this and people in charge need to police these things fast faster and the question is how our democratic processes (slow) deal with it.