I think what we are witnessing here isn’t simply a case of we’re-too-old-to-know-the-kid, at least not just. This is also the result of the market fragmentation, the compartmentalisation that comes with streaming and the internet. Airplay charts are no longer indicative what people actually listen to; the streaming services provide us with everything we want to hear, everything we like - in fact only what we like. We need not listen to anything else any more, why should we?
Consequently, you can be interested in music, follow events and styles and people and newcomers - and still not be aware of Eilish’s existence or significance within the market if you don’t happen to be industry-related yourself. Your music stream plays the artists the algorithm tells it to, you buy the things Amazon - on the basis of algorithms - pitches you. And you go to the clubs and pubs where they play the stuff you and your friends like. Just as you, if you still listen to radio, pick stations with that same program.
Eilish singing a Bond song is perhaps one of the few occasions where people outside her bubble get to listen to something outside their bubble.