Knowing history is essential to understanding current systems of oppression. I do agree, certain things happened so long ago that we need to let go of them so we can progress and move on.
For example:
What happened to the Native Americans was long ago, and the Civil War was a long time ago. People need to stop living in the past.
However, when people are ready to let go of their offensive mascots and things like the tomahawk chop and instead, respect Native sovereignty and treaty rights, and let go of their confederate flags, statues, monuments, school names, and road names that memorialize and glorify enslavers and perpetrators of mass unalivings, I suspect people will be ready to talk less about history and systemic racism. But until then…