The low birth rate problem is real, watch Peter Zeihan, it is his favorite topic, he has been talking about it for years that there's no economical model for this and we don't know how a nation will function when everyone is retired and no one is on workforce.

He actually believes that it's anyone figures out or it will be South Korea.

Also South Korea and Japan aren't undemocratic, but yeah this problem is very big there.

US has a low birth rate as well, but that was compensated by immigrants (which trump goes after)