Immigrants do bring important social and cultural capital. But nobody here is arguing in favor of no immigration.

The standard among countries all over the world is to regulate the flow of immigration via immigration law and deportation of people who violate that law.

How could a massive influx of people happening faster than a system can react not strain the system? I saw this firsthand in schools and hospitals where I grew up, and there are numerous examples throughout history from around the world of the disruption it can cause.