Is it possible that different parts of the world, with different ethnic and migratory histories, might have different dynamics that lead groups to wind up in impoverished situations? Once groups of people are in poverty, yes, I would expect the issues you mention: lower educational outcomes, increased welfare reliance, and increased crime rates.
In the US, the combined demographic trend of Black, urban, and "in poverty" can be traced in substantial part to specific racist policies in the New Deal and post-WWII eras. There's more detail available, but:
a) a substantial amount of government subsidy and policy in those periods was designed to encourage people (especially young families started post-war) to move out of cities, buy land, and raise families there (through low interest rates, development subsidies, etc). This allowed the people who benefited from those policies to start building generational wealth, and essentially created the single-family self-owned non-commercially-functional lot as the fundamental unit of the suburbs.
b) The benefits of many of those policies were both openly and subtly denied to black people, all over the country. Many of the New Deal and post-WWII policies explicitly excluded black people from benefiting. Additionally, redlining (where banks had explicit policies that denied mortgages to black people) and deed covenants (where developers and communities explicitly disallowed sales to black families). This prevented those families from benefiting from the wealth injection I mentioned earlier, occurred all over the country, and was only banned in 1968.
c) After that, poverty is a pretty easy steady state to maintain for specific groups. You just need long-term, focused policing strategies, constant downward pressure on educational and municipal funding, and policies that encourage urban real estate consolidation (and thus rentership).
Where is the argument that this isn't an example of systematic racism denying black people many of the benefits available to the rest of modern American society?
The argument isn't that this was applied to all African American people, the argument is that it was applied to enough to create a correlated gap.