I regret that some Native Americans still live in poverty. Well, guess what, they are hardly alone in that.
Again, I'm giving a Canadian perspective here, as I have more knowledge of it (but even then, less than I ought to).
It is not simply that some First Nations people live in poverty. Even if we dismiss all of the events from colonial times as ancient history (which we shouldn't), we only need to look back around half a century to when a generation of children were stolen from their parents and placed in 'residential schools'. Plenty died (you don't have to go far to find graveyards for unidentified babies and children) and many of the survivors, raised without their families, alienated from their culture and exposed to neglect and abuse, have PTSD.
You then have a generation of people, many of whom were raised without any real concept of parenthood and still suffering from PTSD, raising families of their own, but often not well equipped to do so. So the trauma become intergenerational.
It is not just that a very disproportionate number of First Nations people live in poverty, but there are also disproportionate rates of suicide, violence, substance abuse, etc. And of course, the ongoing racism.
I really feel like I am not adequately expressing the ongoing and real effects of current and historic (but within living memory) discrimination of First Nations justice, but needless to say it goes far beyond some of them living in poverty.