The difference between those OECD countries is that they allow migration. Nationalistic and racist temper tantrums notwithstanding, those countries are bolstering their working age ranks with migrants. China is distinctly anti-migration. So they’ve been digging a giant hole that’s going to take a LOT to fill. And they haven’t even stopped digging yet (first rule of getting out of a hole!)

So, could China change that stance as a way to mitigate the issue? Sure. But they better up their human rights record or they are only going to attract the most desperate of migrant with no other options. That doesn’t bode well for a strong economic engine. Though cheap exploitable labor does help [shrug]