Lots of people eat meat today. I can imagine a future where this is seen as immoral and not following the golden rule. But for some reason, humans currently choose not to apply the golden rule to animals.
Similarly in the past, they didn’t apply it to indigenous people.
How far back in time can you go to right wrongs? Everybody has ancestors who have done wrong. Indigenous Australians had wars before white people arrived.
At some point you have to leave the past in the past and build a more equitable world for all, today.