I think there’s pretty common and clear data on why unlimited immigration is harmful to the receiving country [0] (tl;dr; lowers wages and increases costs for non-immigrants).
The question is whether it’s worth it for the obvious benefit to immigrants. So it may be a net benefit when factoring the improvements to people who immigrate in.
The US benefited greatly from open immigration 100+ years ago because they weren’t that great and there wasn’t much to lose. So it’s apples to oranges of open immigration then to open immigration now. Back then there were no government services and land was literally given out for free.
The question is whether it’s worth it for the obvious benefit to immigrants. So it may be a net benefit when factoring the improvements to people who immigrate in.
The US benefited greatly from open immigration 100+ years ago because they weren’t that great and there wasn’t much to lose. So it’s apples to oranges of open immigration then to open immigration now. Back then there were no government services and land was literally given out for free.
[0] https://www.investopedia.com/financial-edge/0809/3-ways-immi...