there are laws in place and illegal immigrants can't work due to the way the system is set up.
Nominally that’s true in the US also, but here there’s a large informal underground economy utilizing cash and alternatives to cash like drugs, guns, and sex. Needless to say, way more corruption here than Finland. In some ways, the US can be seen as somewhat of a failed state.
The state is successful - the people within that state.... less so.
The only reason for most governments to follow in the footsteps of the US, is to take more control for the state.