I keep seeing posts about drivers playing music, and not being able to hear much going on in terms of traffic around them, as an explanation for earbud use making little difference.
I don't buy the comparison/analogy - cars are much larger and more visible to each other. Yeah I know, many cyclists wear safety vests and bright lights. It doesn't always help. I have also read about motorcyclists complaining how they are frequently not seen by car traffic, even though plainly visible. A fair number of drivers simply don't look out for other traffic other than cars and trucks, particularly if they are not used to seeing them much as part of their daily driving routine.