Why Is There Racism?

I don't think racism should even exist anymore honestly.
The days of institutionalized racial separation and mass genocide of an entire race is over, except for those few exceptions in war-torn countries. But in America, Austrailia and everywhere else, there's no continent-wide slavery or anything of the same kind.
Sure - our grandparents and relatives suffered through it, but what good is trying to 'avenge' them by inflicting racism upon the opposite group? I find that in a lot of places, this is what's happening.
All races have suffered, and have managed to make peace and move on, hence we're here today.

So often I hear people talk about how oppressed they are and how X group would not let them speak out and things.... but they're talking freely on a platform made by that group. If there was some kind of worldwide mass genocide and racism going on, they wouldn't have the chance to.
People just need to make peace and accept what's happened in the past. 99.999% of the people on Earth who've had relatives who were discriminated against or were those discriminating are long gone. What's the point of bringing back what you're trying to 'get rid of'? Just to prove some point for someone 6ft underground?
I honestly don't understand it worldwide, where I could easily understand it happening in wartorn countries. Why? I have no idea.