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.
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.
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).