At what point do we start calling it a concentration camp system ? 60%? 80%?

It depends on answers to questions like “are these groups actually committing a disproportionate amount of the crime?”

And I wouldn’t rush to the notion that you need to be justified in using hyperbolic/metaphorical language before you can criticize the problem.

Why would black or indigenous people as a group commit more crimes?

Is that a serious question?

Why would kids growing up in a remote community with no work, surrounded by drug and alcohol abuse, in a culture that tolerates child sex abuse, whose brains are cooked from day one by FASD and inhalants _not_ commit more crime.

There may be well elements within certain cultures that appear on the surface to tolerate child abuse to a degree that seems alarming, but it's a stretch to claim any culture as a whole does so (and at any rate, first nation peoples in Australia emphatically do not share a single culture).

Socioeconomic factors are the most obvious. The second is the (currently) taboo cultural issue of fatherhood and stable families in these communities. I won’t speculate any more, but I recommend Glenn Loury’s discussions on this topic:

[1] https://youtu.be/LC4Qxq0KMBc

[2] https://youtu.be/lOKiKZeYZbU

If we really knew the answer to that we'd probably have worked out how to solve the problem of higher incarceration rates. At the end of the day though white colonists took away their mode of existence that had worked for them for 10s of 1000s of years. Those have chosen to fully adopt the trappings of modern/Western civilization have done well enough for themselves generally, but is it reasonable to expect they should all make that choice?

In the US, the idea is that poor people commit more crimes than rich people, and whites are more likely to be rich. Whether that is actually true, I have no idea.