Shutting down polluting businesses, relocating others away from where people live, and traffic congestion control are all valid approaches to air pollution control, used not only in China but around the world. Not sure why you need to put scare quotes around the word "solved".

Optical components are already used in some parts of servers, in interconnects. But I don't expect them to replace silicon for general purpose processing ever. One thing that's never noted in these scientific press releases is that optical components are huge. The wavelength of light is about a micron, i.e. a thousand times larger than the feature sizes of silicon electronics. This limitation can't be easily overcome.