I think the larger issue is that the user base for Soulseek is aging, and the younger generations simply don't have any interest in collecting physical (or digital in this case) media.
I'm nearly 70 and have been collecting and trading for 40+ years. I still find people with large, impressive collections on slsk, but they are becoming more and more rare, and they usually turn out to be people close to my age, or over 40 anyway. Streaming is the future, and file-sharing is becoming a thing of the past.
The same can be said of the BT sites and DC++ hubs, which have largely disappeared since their heyday ten to fifteen years ago. (DC++ on Mac is now impossible, for example, as there are no longer any clients being actively supported).
I'm very grateful that slsk IS supported and has this community (if only to gripe in LOL).