> we're all expecting China needs to invade Taiwan soon

Ah yes, China has a track record of invading countries.

> or they will run out of soldiers because of the one child policies of the 70s/80s

As opposed to NATO countries who have a steady increase in the number of young conscripts.

> Meanwhile, Ukraine is holding up against a "modern" army with quickly assembled drones.

I don't know why you put modern in parentheses. Russia did make a mistake of not adopting cheap drones earlier in the war. But Russians were the first to use optic fiber drones resistant to electronic warfare which gave them an edge during Summer offensive last year. Ukrainians have since caught up and their allies were able to supply them with large number of drones. But both Ukraine and Russia rely primarily on drone warfare and artillery becomes less important for both sides. Which all explains the static state of this war.