Basically, they have seen decreased sales, increased streaming, and no increase in touring opportunities due to streaming services.
The end result is that I don't know any artist very well, although I'm well versed in the subgenre. I have no desire to go to a show, as I don't know any artists.
Buying a CD, while a bigger decision, almost entrenches you as a fan. I'm much more likely to want to go to a Taylor Swift concert if I've listened to her CD 100 times (and I'm almost certainly not going to listen to ANY album 100 times with Spotify).
Neither model is better than the other to me. But they are different, and value accrues in different ways for the models.
I guess that the difference might come from the fact I've never been a big buyer of CDs, growing up in Eastern Europe meant that I couldn't really afford music so pirating MP3's was the norm.
I've done that on Spotify. I hear a song I like and go to the entire album, to find I hate the rest of the album. That's fine. That one song goes in my playlist and I listen to it over and over again, and the artist gets paid for making a song I enjoy, rather than me not buying their album because I know there is only one song I will enjoy.