> As you admit, “The US has its own problems”, so it is not successful

That's not at all what I was saying. I believe the US is wildly successful in integrating immigrants, since it is a nation of immigrants after all. Even the native population, which, despite what you said, was not entirely "killed". The indigenous population today owns a significant portion of land in the US and many tribes benefit significantly from using it or leasing it out (speaking from personal experience, the Agua Caliente and Apache tribes). Whether or not those tribes are "flourishing" is another fascinating story, but they certainly have the resources and potential.

I know that you sincerely believe in mixing up everyone in the same bag, but there are several bags. USA is no more successful than Europe at mixing immigrants. But USA has chosen for a long time that its immigrants were Irish, for example. And was mostly unsuccessful at integrating Mexicans, a lot of whom aren’t even given documents. What’s the difference between an Irish immigrant and an Algerian immigrant? I’ll leave it to your imagination but you can take all of the criminals from one population, the worst ones, ship them on a desert island, and you get Australia. While you can take all the best people from the other, give them wealth and infrastructure, schools and culture, and not have a single one that contributes to the home country.

USA has been successful at integrating the first kind, and the second one has just performed a nice illustration of their skills in New Orleans, like they do in my home country every year, and now every month, and one even said yesterday “We will rape all French people.”

This whole narrative of “our ancestors sucked, we now need to own that guilt” seems like a backwards way of moving forward.