In the US, that is how hard it is to get a government benefit like unemployment or food stamps, but public schools are one exception. There have been several states that have passed laws banning undocumented immigrant, but those laws were ruled to be unconstitutional by the US Supreme Court in 1981 because to deny education to these children would ”deny them the ability to live within the structure of our civic institutions, and foreclose any realistic possibility that they will contribute in even the smallest way to the progress of our Nation." More info here: https://www.americanimmigrationcouncil.org/research/plyler-v.... As you can imagine, people who hate immigrants also hate that court decision, but it's the law of the land and I think it is fair.

The case with employment is pretty different, I don't know much about it other than that the employers figure out how to pay people with cash in a way that they're able to not get caught very often.

But really my point is just that undocumented immigrants work incredibly hard at essential jobs and have very difficult lives, and hating them for not going through a long legal process that's usually not even open to them is unfair.