Canada

The trouble is our current demographics mean that reducing immigration would have massive downsides to the economy too.

There are just too many people retiring (now and over the next decade). Without immigration to have a large enough workforce to support the people retiring, the economy will contract. Contracting economies are terrible for citizens and their countries.

The on top of that, the people retiring have a proportionally large amount of wealth. That will cause a lot of demand on our economy. If we do not have equally high immigration to increase the supply of our economy, inflation will go very high to balance supply and demand by decreasing the value of retirees savings.

Not an easy problem to deal with, big tradeoffs every way. But compared to other countries we are better situated because we can avoid the worst tradeoffs by using immigration to solve this problem. If we can figure out how to significantly increase the amount and density of our housing, Canada will be in a great position globally.