I'm not sure if there's enough data to conclude one way or another.

There are heaps of cherry picked examples that showcase each side. For example, Albert Einstein ended up being a quite alright American immigrant, Elon Musk is also another great example of a successful immigrant in the US... also Steve Jobs was the son of a Syrian immigrant, etc...

I think the main issue is that people see immigrants as different, as a "us vs them" mentality, when in reality, they are basically the same.

Of course there are many immigrants causing issues in foreign countries, but also the native population is causing issues there as well. In the same way, immigrants and natives are both doing great things as well.