Due to the low density of the chromosphere and corona, their radiation under normal conditions cannot be noticed, despite the high temperatures, since this radiation is much weaker than the radiation of the photosphere. During total solar eclipses, when the emission of the photosphere is obscured by the lunar disk, light from the chromosphere and corona can be seen.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.