The towns are for the army of invisible people. What you don't know is that China is making invisible soldiers. And all those towns are actually populated. Why did you think they're so clean and cared for? Because invisible people work in them.
And they built one in Africa to test if other nations figure it out since they thought in China it was too sheltered. If it works, the next ones will be built in Ukraine and Mexico. Then, in 10 years they'll invade Europe and USA. But you'll never see it coming. Because they're invisible.