First, that Spotify doesn't make clear when a track is produced by a Spotify "ghost artist".
And second, Spotify is in an unfair position as both the controller of the marketplace/platform, and as a participant on it. The allegation in this article is that Spotify are using their platform position to promote their own PFC program tracks over third party artists/labels.
To be clear, it's not necessarily consumers who are being harmed here. These tracks are supposedly targeted to cases where the consumer doesn't really care that much about the songs that are being played. Rather the party harmed are third party artists/labels who are competing for Spotify playlist space on an uneven playing field.
GP asked how it was different from what Walmart or Amazon are doing, but what you describe is precisely the same as what Walmart and Amazon do. I go to my local Kroger and there are a bunch of Kroger brand knock offs of the “name brand” stuff, being promoted heavily. Kroger makes more money off that stuff because they don’t have to split the profits. Nobody’s complaining that this is unfair.
Your point #1 still stands though, and if the slop in question was clearly labeled as “spotify originals” or something and was something you could easily filter out, I’m sure far fewer people would have an issue with it. The issue is the deception, not that they are pushing their own slop on people.