I like Billie Eilish's music and think her brother is a decent producer, but you can't really compare the two in terms of song writing. I don't think there's a single Billie Eilish song that people are going to remember in five years, let alone after 50 years. I did enjoy this video about how they made bad guy:
https://www.youtube.com/watch?v=kpx2-EMfdbg
But there are literally _thousands_ of videos of producers making songs on youtube now.