The details would be a nightmare, but the rest of it sounds like a dream.
Of course, the devil is in the details. But let's look at the broad strokes.
When countries can trade goods and services freely, they become more prosperous.
That's because, as professor Ben Powell explains in the video, more people have more opportunities to spend and invest their money. Companies make more money from the increased sales, and they're able to reinvest those profits into growing their business (like hiring new employees).
When workers can trade their labor freely, they also become more prosperous.
A person who sells fruit in a rich country will make much more money than a person who sells fruit in a poor country. Then that person can use those additional wages in ways to do things like pay rent, buy groceries, or see a movie, thereby boosting their local economy.
That person may even send money to family in their home country, enabling that family to boost their local economy in the same way.
Add them both together, and you have an economy that's buzz-buzz-buzzing.
If workers can provide their labor to the highest bidder without complex application processes and long waiting lists, everyone could contribute to amplifying their local, national, and global economy.
But we're not just talking about low-skill workers in the poorest of poor countries. Why shouldn't a teacher in the U.S. be able to try teaching in Luxembourg? That's a near doubling of their salary!
But what about native-born workers?
Powell, who teaches at Texas Tech University, says this:
"Some worry that increased immigration would harm native-born workers. However most studies show that on the whole, these harms are non-existent or minor, temporary, and clustered on only a small portion of the population."
But those are real people! And those harms mean something to them and their families. No wonder there's so much resistance to changes to immigration laws. Still it's obvious that we'd miss out on a lot of economic activity if we keep things the way they are.
We need to craft immigration laws that balance helping our economies grow, providing economic opportunities to those who need them most, and helping those who might be negatively affected by the changes (no matter how "minor, temporary, or clustered").