Avril Lavigne told in an interview that Billie Eilish is similar to her in that they are both authentic compared to their contemporaries. She also told that when she entered the industry she was quite different than the other artists because everyone was bubblegum pop and had a bunch of dancers around them, though Avril was dressing in dickies and converses like a dude.
The youtube channel called ''Pop Dissected'' examined this similarity on a deeper level. What it argues is that similar to Avril Lavigne, Billie Eilish has the same rebellion and honesty in creating her own music, fashion, and image. The analogy is first drawn by mentioning the musical environment in which they emerged. In 2002, when Avril released her first album ''Let Go'', the industry was mainly dominated by Britney Spears, Beyonce, Kelly Clarkson, and Celine Dion, all of who were making pop music. In the early 2000s, it is further mentioned, there was a standard image of how female pop artists presented themselves. They were mostly alluring, spunky and glamorous.
However, when Avril came with her pop-punk driven music and look in 2002, she was able to create a counterculture and make it challenge the mainstream image of how popular female artists could sing and look. She was dark and edgy, which separated her from the mainstream cheerful and alluring pop artists.
So how is Billie Eilish similar to this pop-punk artist of the early 2000s ? Well, though Billie Eilish hasn't broken the current trend of hip-hop and trap-influenced tracks like Avril did back then with her punk style, Billie Eilish changed the conventional structure of this mainstream style by leaving the successive order of verse-chorus-bridge. She creates her own format and doesn't try to fit in the traditional structure of a song since she has her own unique style. She is dark and edgy just like Avril was, in contrast to the contemporary hip-hop and trap female artists who are mostly racy and sensual. Moreover, similar to Avril whose lyrics were raw and vulnerable, Billie Eilish has honest and relatable lyrics that help them become more impactful.
Sources:
https://www.facebook.com/BillieEilishfanpage/photos/a.259200138013419/419528531980578/?type=3&theater
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.flickr.com%2Fphotos%2Fjuancarlosequihua%2F3432561743&psig=AOvVaw3Ct3Rq36TXzfXKFRKB9MbP&ust=1581862433565000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCKiVmvre0-cCFQAAAAAdAAAAABAD
The Avril comparisons are a really hard sell for me honestly. Avril was maybe pushing a countercultural image, but that's where the comparisons really end. Growing up when Avril's debut hit, her whole shtick felt like it was consciously designed to be a commercially digestible version of teen angst positioned to maximize sales at Hot Topic. In short, it never felt authentic. A former country singer whose songwriters and marketing team designed to be countercultural but in that way that always felt hollow to me.
Eilish however, no matter how you feel about her music (by personal opinion varies from song to song), has never felt in authentic. The entire album was written by both her and her brother, not a song writing team trying to develop a pop star. Her image is driven both out of self expression and a desire not to be objectified in the way most female pop stars are.
If I had to make a comparison, I would liken Eilish more to Fiona Apple. It feels a lot more adept of a comparison, especially in the song writing.
Oh thanks for pointing this out since I didn't know that Avril didn't write her all songs at all. I've just checked some sources in the internet and it seems that we can't actually make a comparison in terms of songwriting, you are right.