The reference is to allow for comparison. Most people have no feeling for absolute statistics. Comparing something in relative terms to the numbers for something with which they have a daily experience, helps to provide context for the scale or severity of a problem.
> The two are not comparable problems and each requires completely different solutions.
Nobody said they require the same solution. The point is to grasp the scale of the problem.
> I think a helpful comparison is examining how in other first world countries the police kill almost nobody. Per capita, more people are killed by law enforcement in the US than in any other 1st world country by a huge margin.
You'll get little sympathy for people actively fighting back and resisting arrest. I think it's more relevant to look at the number of unarmed people killed by law enforcement: https://www.wsj.com/articles/the-myth-of-systemic-police-rac...
In 2019 that was 28 people (9 black, 19 white). Again, that's in a country of 330,000,000 people. Yes, it is disproportionately black vs the general population. But there are other factors like income and housing density that come into play. And in absolute terms it's a very small number of the total population.
Yes, we should be reducing that further but it's not a problem of police randomly killing blacks. And it's nowhere near the scale of other problems that are killing people or blacks specifically. Last year in Chicago alone, there were 349 black homicides.