US also put a lot of roadblocks in a way of highly skilled immigration. For example, check the waiting time of Indian engineers to obtain Green card.
> These people are no more a solution than our idealistic weebs.
Not sure I agree with this assessment. Unskilled immigrants tend to be over-represented on hard low-paying jobs, both in EU and US. Someone has to build, pave roads, cook, deliver, tend of elderly, etc.
It was enough that, even with the on-off nature of the work (you're not getting paid when nothing's getting built), they could easily raise a large family very comfortably. Now a day construction in the US pays awfully and a big factor is the large number of illegal migrants working in it for sub-market wages. So you're talking about the necessity of solving a problem by expanding the thing that caused it.
It's very difficult to predict what demographic collapse will look like in a place like the US, but one general trend that might inform us is that fertility within places like the US remains strongly inversely correlated with income. Those who are earning a lot aren't having children, those who aren't earning much - are. Pair that alongside fairly low upward mobility, and again I think it's unlikely that significant numbers of unskilled workers will have any real value in the future (or present).
Yet there are many western countries where the issue is how to prevent all the people attempting to get in from doing so.