Earlier quoted context omitted.
Europe doesn't have a population collapse. They make up the difference with immigration, as does Canada and the US. Japan and China do not.
Most immigration to Europe is incredibly low-bar unskilled economic chancers interested in exploiting the welfare state, not skilled workers, doctors and engineers like you get in US and Canada which have stricter immigration policies.
That is patently false. Especially the Western and Northern EU countries have a massive influx of high-skill workers (doctors, programmers, engineers) from both Eastern EU countries (which will dry up sooner rather than later, to be fair, with terrible population growth already happening for more than a decade in places like Romania), but also from neighboring countries - Turkey being the largest source.
Even the so hated "refugee crisis" from Syria saw mostly middle-class Syrians moving to Europe (putting it in fear quotes since the whole of the EU had fewer refugees than Turkey alone to accept).