Re the first paragraph: It's good you think that because that literally is what we teach and should believe. People who believe otherwise are mistaken. Even so

Re the first paragraph: It's good you think that because that literally is what we teach and should believe. People who believe otherwise are mistaken. Even so called fundamental physics is studied within an approximation almost always. The moment you say "photon" you're making an approximation (usually monochromatic and plane wave without sources, in the infrared region, and so on). Physicists who think otherwise simply do not understand what they are doing.