Streaming audio services decimated private trackers like What and Waffles. Anecdotally, I know a number of people who passed up torrenting GoT this year to just stream from HBO Go for the first time.
Waffles didn't innovate. The site that launched after Oink shutdown is largely the same site that is up today (figuratively, I'm sure it'll be back at some point).
That said, I agree it was a music fan's heaven. Just as Oink was before it. It is sad how badly Apple Music's recommendation system is, how bloated it is with recording industry pushed crap.
The worst part isn't that What is gone, it's that What is gone and nothing can replace it. Like with older games that can't be purchased legally online, the rightsholders have kept us from consuming that content at all. In order to preserve their absolute right to distribute it for money!
The number of people here suggesting Apple Music would have killed it anyway or that Tidal etc is an adequate replacement shows just how effectively the rightsholders have deluded us all again. The currently available streaming services are almost entirely incomparable to the collection once available at What, it's like comparing your local library to the statewide database.
the recommendations were pretty well thought out even if not my cup of tea, and you could actually see what was new or active without having to worry about the piper being paid.
if you wanted to listen to your weirdly specific music tastes, it was perfect for that.
Taking this setup down would require someone to take every single person/node down, although it might have more issues with availability.
Citation needed.
Private trackers are and were always for data hoarders and bitrate freaks. The average Spotify subscriber was never the target audience of private trackers.
Another big change for me was the industry got wise to leaks. Now when an album leaks, the labels have a plan to immediately offer it for streaming on a major service or even media partner like NPR.
One of the major values of private Audio trackers was you got to hear stuff way before other people. Even this has been largely taken away. (Though sometimes the previews are now only a few songs)
EDIT: the loss of the forums, knowledge, metadata is truly heartbreaking... i really can't think about it too much