The Dawes Severalty Act of 1887 failed because what?

Answer 1

The land granted to most allottees was not sufficient for economic viability, and division of land between heirs upon the allottees' deaths resulted in land fractionalization. Most allotment land, which could be sold after a statutory period of 25 years, was eventually sold to non-Native buyers at bargain prices. Additionally, land deemed to be "surplus" beyond what was needed for allotment was opened to white settlers, though the profits from the sales of these lands were often invested in programs meant to aid the American Indians. Native Americans lost, over the 47 years of the Act's life, about 90 million acres (360,000 km²) of treaty land, or about two-thirds of the 1887 land base. About 90,000 Indians were made landless

Answer 2

western native Americans were not used to settled agricultural life