It probably wouldn't be to the benefit of China as a country. But that might not matter given how much Xi has consolidated power - the question is whether it benefits him. And if he wants to end up in the history books as "great leader who completed reunification of the country" or some such, he might have to rush even if that significantly increases the costs.

(There are good reasons to believe that something similar wrt Putin is the primary motivation behind the war in Ukraine, BTW.)

That's more true of Taiwan's population. Taiwan's fertility rate is set to be the world's lowest.[1] So it doesn't seem like the population is Taiwan's advantage.

[1] https://www.japantimes.co.jp/news/2021/04/21/asia-pacific/so...

You take what you can while you're powerful, it's easier to defend what you have when you're weak.

Russia is in the exact same boat, they were running out of time and young people as well

That is why I think they might be more inclined to conduct a blockade.