I don't think radio killed the theater star, radio got them to record, but music quality remains.
Video killed the radio star because physical appearance of the radio star began to matter, it came to a point where it made music quality become secondary to looks.
Internet did not kill the video star, they just got another screen to show themselves in. This is the problem that quality music faces today. The nice-looking-mediocre artists get to overshadow the average-looking-amazing ones.