This seems to be a right wing meme that's been floating around on the internet. "The Indians were just as brutal. They conquered and massacred and enslaved each other all the time. What they did to each other was no different from what the Europeans did to them." The unsaid implication being: STFU, snowflake.
For starters, I suppose there was a difference of sheer scale. 'Quantity has a quality all its own', as the aphorism goes. Beyond that, I don't think this claim passes the smell test, but then I don't feel qualified to get into it.
I know that historians aren't supposed to pass normative judgment, but there is an explicit historic claim being made here.
Regarding slavery, let me give one example: you may be interested in this previous answer to a question by me. This specifically concerns the Maya world, but the bottom line is that while slavery existed in Maya society prior to colonialism there was nothing remotely resembling the large scale chattel slavery and slave markets that the Spanish introduced.
There are numerous other examples. Here is a very good post by u/Anthropology_Nerd about the transformation of slavery in the American South.