> Germany's population pyramid is significantly more top heavy as is China's.

I must be looking at a different graph, because the UK looks like it clearly has less people under 10, than over 60, which does not happen in China.

> Not to mention, the UK is much better at assimilating immigrants than Germany and especially China.

That is debatable.

UK immigration numbers are quite similar to Germany, with 7.7% of non EU immigrants, vs 7.8% [0]. This percentage is lower than other countries like Spain or Greece. Crime rates among immigrants in the UK seem to be similar to those in other countries, as are poverty rates.

[0] https://en.wikipedia.org/wiki/Modern_immigration_to_the_Unit...

>I must be looking at a different graph, because the UK looks like it clearly has less people under 10, than over 60, which does not happen in China.

The important bit is China's massive spike between 30 & 57. What's the plan for the next 30 years?

It's not just about raw numbers, but how well those immigrants integrate into the target country

> The important bit is China's massive spike between 30 & 57. What's the plan for the next 30 years?

I don't know, but again, given the fertility rate in the UK, and the recent clamp on immigration, I don't see how they could fare better.

> It's not just about raw numbers, but how well those immigrants integrate into the target country

Right, but you have not been able to justify either. If there are no metrics on how "well" immigrants integrate, then the point is moot.

> the UK is much better at assimilating immigrants than Germany and especially China.

Doubt there will be any immigrants left, after crazy stuff like sending immigrants to Rwanda and attack them publicly for any and every failure of the economy.

Also from a quick read, immigration has already filled the fertility gap in Germany and after the Ukraine war it's giving a surplus too.