My answer may well sound cold and cynical, but here goes.
I did a history degree, and we've been living in a live action GCSE history question since 2016.
The whole thing is an immensely complex series of trends and triggers. I'm actually far more of the philosophy not that Black Lives Matter or All Lives Matter, but that fundamentally on a historical level No Lives Matter. We all end up dead, and as an atheist, I'm of the opinion that that's it - one shot at life.
Unfairness is pretty much hard coded into human societies and has been for the entirety of their existence. There's never been a nice and lovely and fair society, and the present global combination of wealth distribution, technology, environmental issues and large populations make it near bloody impossible to achieve. There are two few good people, too few intelligent and educated people, and too many mechanisms for the bad and the powerful to prevent change and manipulate the stupid and the vulnerable. It will take a truly seismic effect - a really decimating pandemic that can't be managed like this one, or a proper cataclysmic environmental failure, to hit a fundamental reset button on human society (assuming it isn't wiped out). And even then, rebuilding human society in a good model relies on the ragged remains of humanity consisting of people with the intelligence and resources to do so and the good will to do it right.
Now that is obviously highly depressing, but within that there are still good people, still good things, still good lives to be lived. Humanity is an interesting but flawed species, and right now the flaws are especially evident and exploitable - off the back of their own inventions, thank you social media!
As a person who has studied and evaluated history and anthropology and come to those conclusions... Yeah, I have very little incentive to leave the house to go shout about injustice, when I have shit to do and a bad headache.