Canada

Economics Explained recently did a video reviewing Canada's immigration policies. Most advanced economies have low birthrates and make up for it with immigration. Accepting an immigrant is (economically) much better than someone having a baby. A baby needs decades before it contributes to the economy. An immigrant is often educated and skilled in a desired field and will immediately contribute to the economy.

However, Canada might be the first country to stumble upon some downsides to immigration. Mainly, student visas might not contribute as much to the economy as once thought, Canadian immigrants leave to work in the US at incredibly high rates, and Canadian metropolitan cities are some of the most expensive to live in worldwide and immigration is exacerbating the issue (the issue isn't immigration though, it's a focus on building single detached family homes over high density housing).

Just don't scroll down into the comment section. It's mostly just people being racist. I sincerely hope those comments aren't coming from Canadians. (The channel also did a video on why African countries struggle economically a few days later and the comment section was even worse)