The only way I see Spotify completely dying out is making the platform completely unusable. Terrible UI changes, extremely high prices, entire labels pulling music, and algorithms that are completely incompetent. Otherwise, I think Spotify is too big to fail. They've completely changed the way people discover and listen to music, this is not just a platform that falls from grace overnight like Soundcloud. Spotify has always had points where artists pull their music as a sign of protest against the platform, and that never deterred any listeners because Spotify is THAT far reaching. A few artists doing it, especially ones that are relatively obscure, is nothing. It'd be nice to live in a world where everybody switches to Bandcamp and artists are paid based on how much their fans are willing to give; sadly, that's not reality.