> They should do some actually police work. This kind of "Papers, please" approach to immigration enforcement is dystopian.

Why it’s dystopian? It’s literally how it’s done in other places as well.

I agree that the government has to go through and punish those who employ illegal immigrants too to disincentivize unauthorized employment, but it doesn’t have to be only one avenue.

> Why isn't the FBI or local police?

I do not know where you live, but lately crimes in the US in many jurisdictions are not prosecuted, and repeat offenders are not punished. Coupled with the fact that many cities forbid their local law enforcement to cooperate with immigration, I am not sure how can local police do anything.

If an illegal immigrant committed a crime it is a failure of both local LEO and immigration. It doesn’t have to be only one.