When I was a teenager, music was the most important thing in my life. My ex's daughter is 15 and don't like popular music at all - except for Billie Eilish. She actually even bought a CD just to have a physical item, even though she has access to every bit of content on Spotify, Youtube etc.
That's what made me look this artist up and realize how incredibly popular she is with the younger audience. I'm 40, so I'm lost in terms of finding new music. There aren't record stores anymore and MTV stopped being relevant 15 years ago. My "Discover weekly" spotify playlist only play stuff I already know, plus the occasional Finnish (!) pop song, and the "New releases" playlist is filled with re-releases of stuff that got automatically removed from my playlists because Spotify's license for it got changed or whatever reason.
I think that most people in this thread - including me - overestimate our opinions' relevancy to Billie Eilish and her fans. They don't give a sh*t about Van halen (nor should they), Michael Jackson, Aretha Franklin, Pink Floyd or whichever band we got hooked on and still consider the world's greatest. We are busy trying to get to see all of our idols once more before they die, while the kids are discovering their own music and it doesn't work like it used to. Just like when my generation sat in front of MTV for hours at a time, much to our parents' dismay.
I think that Billy Eilish will very well fill the largest stadiums in my part of the world whenever she decides to go on a world tour, and that there will be a lot of confused parents in the audience. In fact I checked the tour dates on her site and all of the UK concert next year are already sold out:
https://www.billieeilish.com/
Oh and - I totally agree on Eminem even though he's seen his best days. I was always amused with how popular he is with middle-aged ladies.
There have always been awards for popularity. As for the quality argument - The main problem is who gets to decide what quality is. Clearly most teenagers and the average Macrumors reader disagrees on that particular point.