The real problem is the population explosions in many Third World countries creating surpluses that their decrepit economies and infrastructures simply can't support, which leads them all clamoring to come here or to Europe. What will happen when the population of sub-Saharan Africa increases 2 or 3-fold with Europe and possibly the US as well wide open?
correct, the USA has a population density of 35/km², China has 148/km² and india 420/km²
As to “what will happen” — we already saw that in Europe with the economic migrants from 2011 to 2018.
They came in waves. HOWEVER, the numbers have collapsed due to four reasons
1. better policing of the borders between the EU and outside
2. Better co-operation with Libya etc. who intercept the migrants (and sadly enslave them)
3. Better economic growth within sub-saharan africa
4. More news and horror stories heading back to sub-saharan africa telling people “if you try to go illegally, you will be enslaved, and even if you get there, there are no jobs”
If an economic migrant from Africa no matter how hard-working or law-abiding comes to say Italy illegally, he will not find a job.
Italy is highly automated - you will be hard-pressed to find low-skilled jobs. That means that a large chunk of ITALIANs are unemployed.
For low-skilled Africans, this will not help them - they can’t find jobs in legal or even illegal work. So they are pretty much enslaved or head back with no money. the word goes around.
Instead they are heading to Nigeria, Senegal etc. where the economy is growing.