I guess I should've known that the comment section for a news post like this one on an Apple fan site is not the place to find dispassionate analysis.
Apple advertises their services in places no competing service can, like the Settings area of your iPhone and iPad. And in the bottom tab row of preinstalled software like Music and Fitness. Furthermore, those competitors need to advertise in the App Store if they want extra visibility, which means... paying Apple for a lesser form of visibility than what Apple gives itself. And Apple wants 30% of competitors' subscription fees too!
Meanwhile people on this site will contort into pretzels to explain how this is perfectly legitimate, presumably because they own Apple stock and see it as a part-time job to post propaganda on sites like this.