You're making an irrelevant distinction here. If you buy a CD with a song on it, do you buy the rights to the song? Or a copy?

A copy, right? You own a copy. The music corporation isn't going to show up one day and repo your CD because of X, Y, Z reason. You have unlimited personal use of the copy. Not the rights to the whole song, but just the copy. You can play it in your car. You can play it in your walkman. You can loan it to a friend.

But when you buy a digital copy, your ownership rights are dependent on them. It's more like a lease with terms subject to change whenever the lessor wants, like because they got bought out or they lost the distribution rights or most commonly through pure incompetent inability to maintain the systems that they require you to use in order for you to use your copy.

It's almost impossible to just buy a .wav of a song anymore. Now when you "buy" a song it has a ton of restrictions on it, any one of which could prevent you from playing it. You can't loan it to a friend. You can't play it on a different device unless you log in to their systems. Sometimes you just lose access to it forever with no recourse.

That's what this post is about. Ownership of the copy, not the rights to the original. Literally no one is talking about the rights to the original. You just brought it up out of nowhere.