Not only am I familiar with that thread, you and I actually had a conversation in it 
- though it was a while ago. The thread makes for pretty distressing reading, obviously, but we should be mindful of the fact that its statistical relevance is limited.
The thread contains a long list of isolated incidents. Some of those incidents - I couldn’t say how many, but by my recollection probably quite a lot of them - are undeniably racist in nature. Nobody would argue that there’s no such thing as a racist cop. But they’re also curated by a fairly small group of people, whose political leanings are reasonably similar, and who probably consume many similar news sources. Those news sources, in my experience, tend to give a great deal of coverage to stories of young black men who are mistreated by the cops (as they should!) but tend to give next to no coverage of members of any other demographic who suffer similar mistreatment. If, as I suspect, the incidents in that thread are largely culled from those sources, then the thread will most likely present a skewed picture of the threat cops pose to young black men, compared to the threat they pose to young white, Asian, or Hispanic men.
An examination of the incredibly useful Washington Post Police Shootings database reveals that there’s a wealth of examples of trigger-happy cops shooting white and Hispanic men on extremely flimsy pretexts. For instance, crowmanyclouds references the example of a black man shot for holding a wallet - the implication being that such things just don’t happen to white men in America. But it took me less than a minute to find an example of a white man shot by a cop for holding a wallet. I’ll link to dashcam footage below, but I’ll spoiler box it and break the link because it’s an upsetting video:
To cut a long story short, if you watch the Rittenhouse footage, and your knowledge of police violence is limited to the examples found in the ‘Controversial encounters’ thread, then it’s completely understandable why you might think that a black kid would never have gotten away with doing what Rittenhouse did.
However, when we look at the totality of police violence we see that, actually, trigger-happy cops shoot white and hispanic young men for unjustifiable reasons far too often as well. When you combine that with the evidence already presented that many black people routinely exercise their right to open carry without incident, it becomes much harder to argue either (a) that a black kid who did what Rittenhouse did would’ve been shot by the cops (because black people exercise their right to open carry all the time), or (b) that Rittenhouse only escaped with his life because he was white (because white people are also frequently the victims of badly trained, trigger-happy cops).