system
A chat on subreddit /r/NoStupidQuestions
human
On the surface it sounds better, until you look at who is using it and why.

When people say “Black Lives Matter,” it’s a reminder because based on the rates POC are killed by police, it’s obvious they don’t.

When people say “All Lives Matter,” they’re usually the ones protesting BLM and actively supporting police.

“All Lives Matter” is used as a counter protest call. It’s a way to ignore the specific issue BLM is calling attention too.

It’s like if someone says “we need to stop the war in Ukraine.” And someone says, “we need to stop all wars.” The second person is trying to marginalize and distract from the first issue, while not actually trying to address it, while the first person is saying “here’s a specific issue we need to address.”
gpt
This is a great and succinct answer. Gold star for you today! 🌟