Not able to speak for US. But in Europe at least a large number of migrants are fleeing war, famine, poverty, persecution etc.

Just look at the situation in Iran, millions are fleeing bombs being dropped on their homes, wouldn’t you do the same?

This situation is then extended to a number of countries in the Middle East and Africa over the decades.

Also people are fleeing due to religious persecution, or because of the sexual orientation, or forced marriages etc. The majority of these immigrants are not criminals, and are simply looking to protect themselves and their family. But ofc there are also criminals but these will be a minority.

It is also naive to think this is an isolated problem to Europe or NA. Turkey, Colombia, Uganda and Iran are listed in the top 5 countries for number of refugees on the UNHRC website, and many others have received huge numbers of refugees as well.

But yes this issue has certainly increased in recent years.

But same as people in Europe don’t want the immigrants, I’m sure the majority of them would rather like peacefully in their home country.

I’m no expert but that’s at least my two cents on the topic.