You are right that every industrialized nation is facing a demographic decline. But it is handled differently in Europe than it is handled in the white crown colonies, in the US and in Eastern Asian countries. While those countries select at the border and only let the best ones in, Europe's nanny states are loser magnets and only attract the useless ones that need to be taken care of by those who work. Logically, this drains those countries from their tax payers on the long run. The highly qualified people leave, while there is a steady flow of young people with low or no qualifications from underdeveloped countries to Europe, whose aging taxpayers have to pay them for breathing and breeding.

If you want to peek into the future, then have a look at the kids in the age bracket 0 to 6 years. That is how the society will look 20 years from now. The countries our forefathers fought for are gone. And they are gone just because our forefathers chose to shoot at each other instead of having a beer together and learn from each other instead. He who dies in the field is no longer of any use for his country.

The decline of population in Europe starts around 1916, and the replacement started after WW2 in Britain and somewhat later in Germany. By now it is impossible to reverse, because that would mean increasing the birth rate from 0.9 to 4 children per woman.

While Japan's entire population will decline from 120 Million Japanese to 80 Million Japanese between now and 2050. They try to compensate this decline of population with automation and robotics. In Europe we try to compensate it with immigration. But there are no Chinese workaholics coming to Europe. It's mostly people who often can't even read and write in their own language, let alone being able to develop top products. This means that the old Europeans have to take care of these young people as well. That's your retirement money gone. For ever. Now you don't need to be a prophet to see that the economic downfall of Europe is inevitable, do you?