Just spent some time crunching the numbers and the number of migrants (6 million) is the equivelant of the number of working age people in the UK that were classed as capable of work in 2017 (OK I didn't get the actual number but I took a third of all adults who were out of work which will do). I think Sweden is said to have a 16% migrant population so what's stopping the rest of the west from taking on more?
If there would be a unity within Europe to spread out the refugees to all countries across Europe it would be much more easy to find a solution. But there is no unity. We have countries in Europe that didn't take any refugees since 2015 and the EU has no mechanism to deal with these countries. To find a real solution to immigration and for the refugees we would need to change the EU laws but for that you need a 100% majority which is never going to happen.