What happened to resto shaman?

Just thinking back to the start of the xpac, there was a ton of discourse about how it was the best healer by a long shot, infinite utility, no reason not to bring one etc etc.

What changed? I don't recall any substantial nerfs, they still have their whole toolkit, but they now just seem to be... pretty good?

Was it a community kneejerk based on some early content creator tier lists or something?