You may get different kinds of smoothing with alternative apps. Hallide is popular.
You're really asking for information that just isn't there, so something has to be made up. If this were film, it would be a similar story, except that the light would be spilling onto different grains rather than adjacent pixels. With Digital, at least, you can try the edit tools in Photos, adjusting "Sharpness," and "Definition." "Noise Reduction" is just more smoothing. Other camera and editing apps may give you more choices but, again, it's just making things up.