> I wish Spotify welcomed or collaborated with these archival initiatives.

Spotify licenses the music in their library under specific terms. They don't own it. They can't just decide to give out freely on their own terms.

> Anna's Archive does not compete with Spotify in any way.

I think HN often underestimates the breadth of casual piracy among the general public who want to avoid paying $10/month for a service. There are already numerous tools to stream TV shows and movies from torrents on demand. I have no doubt the same will appear for a giant archive of Spotify music. A lot of people will jump at any chance to cancel their Spotify subscription if they can get close to the same access for free.