I'm not against immigration but it's no solution. You're in Europe. You're trying to replace a workforce that has free education, in a place with high quality education infrastructure, therefore most of them have bachelors and probably at least one or more masters degrees, with essentially illiterate (and i mean this with all due respect) people from a completely different culture who are not prepared to do anything remotely useful for at least 10 years, probably more.
I've literally had migrant refugees from Lebanon, Somalia, Eritrea, Morocco and such as flatmates in Brussels. Some of them are my close friends. They are not remotely prepared to take over 90% of European jobs. You either need social skills, labor skills, language skills or technical skills which they simply do not have. If i was in their shoes, it would take me decades to catch up to how Europeans work.
The migrants come here for what ? Uber eats ? How are they supposed to support themselves ? With government integration money we don't have available ? But say we figure it out and they live and then they will have kids one day. Those kids will behave exactly like the local population. They will go to University, they will be highly qualified, they will be socially adapted to the place, culture and language and, they will also not have kids, just like the locals. So which problem did these migrants solve then ?
So the issue here isn't that we lack people in Europe. It's that our economic doctrine is deficient. We need to change the doctrine, not the people. Immigration will not solve this problem, it will perpetuate it. Young people not having kids is an economic issue that will still happen whether you have a European young person there or a Iraqi young person there. You can't simply transplant a young couple from a country with very high birth rates in a totally different part of the world, subjected to an entirely different set of circumstances and expect them to be the same in Europe. That's not how this works.