According to this video analysis, the peak of China's capability to attack Taiwan will occur in the 2020s, with one cited analysis putting it specifically in 2027, due to demographic and economic trends, and will begin to decline thereafter:They are just venting their frustration. It will be at least 10, much better 20, years before China will be ready to attack Taiwan. But if they wait that long they can take it without a sweat.
Watching that video above I was amazed how aggressive Chine is policing his own citizens outside China. And even hearing about 800 cases of industrial espionage. China is really pushing the limits and you don't hear anything about that in papers.
Similar reasons have possibly influenced Putin to attack Ukraine, as his population is not getting any younger, and Russia would have faced an uphill struggle in maintaining a large military and the industry required to equip it. Therefore, if Russia was going to launch an offensive military operation against Ukraine, the sooner, the better, was likely Putin's thinking. Russia's capability in that regard was only declining. The demographic factors are likely going to influence both sides' ability to sustain the intensity of the conflict over the long term, as those people being lost in it are not being replaced by younger people.
Russia is reported to have abducted tens of thousands of Ukrainian children, to have them forcibly adopted by Russian families, perhaps attempting to mitigate its own demographic implosion, at the expense of Ukraine.