It's not even about "Black Lives" anymore, that was just the original spark that continues to give the riots some semblance of credibility even though BLM itself is a self confessed Communist group. Most of it now is anarchist/communist groups like Antifa (and BLM) and those with severe Trump Derangement Syndrome who think they're saving the world from Nazi's whilst behaving like them.
This is largely what the riots about:
You've got people who've spent the best part of 4-5 years living in a bubble of Trump being called an evil tyrant and how they need to overthrow him to prevent a far right menace that up until this day is largely imaginary, these people don't even listen to other points of view because they find anything that doesn't align with their own beliefs as offensive and far right (which I assume is why they think there's a huge far right threat in the first place).
They spent 3 years hearing how Trump colluded with Russia which proved to be false, there's plenty of corporate media footage of people like Adam Schiff claiming to have seen direct evidence of collusion if you search for it but funnily they never showed any of it to Mueller during his multi-million pound 2 year long investigation.
The impeachment that was nothing other than a bipartisan fraud, that couldn't wait for any actual evidence due to Trump's imminent threat to the constitution but then once passed Pelosi sat on it for a month or two because it was nothing but a media circus.
Something like 95%+ of corporate media coverage about Trump has been negative whilst at the same time independent media where Trump has support is being censored by umm corporations.
Trump had to take a mental health test because they spent weeks making out he was senile and brought to you by the party who are now running Biden who can barely string a coherent sentence together and neither the Democrats or corporate media care one bit.
Strzok and Page of the FBI texting to each other that they'll stop Trump from winning and have an "insurance policy" in case he does.
General Mike Flynn found to be set up by the FBI and later cleared.
FISA warrants to spy on the Trump campaign obtained illegally.
Have I missed anything? I think in a few decades time the last 4-5 years will prove to be an example of a population can be radicalised to the point of violence and uprising based on mostly propaganda.
Oh and things are going to get a lot worse later this year when Biden loses and the Democrats demand for mail-in-voting gives them the excuse that Trump "stole the election" even though they'll spend months saying it's perfectly safe from voter fraud.