It all boils down to the size of the virus particles and the mesh size of your mask materials. The mesh has to be small enough to filter out the virus otherwise the mask ain’t doing squat. Then you have to properly wear the mask and most people are not properly trained in mask use. If you have a beard or facial hair no mask is going to help you.
CDC reports out today state that surgical masks that everyone is wearing today are completely ineffective at filtering out aerosol virus particles. One study of new infections in July found that the majority of people infected ‘always’ or ‘mostly always’ wore a mask.