Licurg: But they still can't make air in big cities breathable...
We're trying. Photocatalysis is a thing that shows a lot of potential, but so far biggest problem is that the UV that is needed for the catalysis is also deteriorating the coating. Indoor coatings that can also be activated with visible light instead of UV are currently in the testing phase, but that means at least 5 more years before it's commercially viable.
Not to mention the fact that other than cleaning the air, there is also work being done on polluting less. Hybrid cars, car engines that shut down when you wait at a red light, only to start "instantly" when you put the car in first gear, better catalysts and so on are also being developed and put into circulation.
As for NeverWet, it is an excellent application, but it requires a new coat every 3-9 months depending on UV exposure, and the coating is whitish, so it might not be suitable for every piece of clothing you have.