what's with the grey font colors

hi

can someone help me understand what is with the 'grey font color' being used all over the place on iOS & macOS?

I have written to apple feedback several times about it, but I just can't understand this. That color makes the font so faint it is very hard to read normally and then one has to 'brighten' the screen at each such occasion. Why can't Apple get rid of this grey color? the other text is in more brighter (?) color, but then that grey comes in which is very difficult to see unless you again go back and increase the screen brightness either on iOS or macOS

this is notifications slider from macOS