I would argue that the reason for this is radio vs streaming. In that time period, radio was king. Radio stations tended to play a very narrow selection of hits

I would argue that the reason for this is radio vs streaming. In that time period, radio was king. Radio stations tended to play a very narrow selection of hits over and over and over until you couldn’t help but remember every word. These songs became ingrained into our culture. If you wanted more, you had to go to the record store, which was still quite limiting. Now, we have streaming, which lowers the barrier between listeners and many thousands of artists. As a result, people are exposed to a much broader variety of music now, meaning it’s less likely that there are hits that everyone knows.