I never listen to music on the radio but I do listen to talk radio a lot and considering the number of listeners that a station like KIRO FM gets here in Seattle I can't imagine FM going away any time soon. My car has HD radio and I live in an area where that cuts in and out. It seamlessly switches between HD Radio and regular FM but it is obvious when the static cuts in that it is no longer receiving the digital signal.
With that said, I don't even listen to the actual broadcast that much anymore. I download the podcasts of all the shows and listen from my iPhone so if FM was turned off tomorrow I imagine I wouldn't care that much. However, with the lack of HD Radio adoption in the US I'm sure many consumers do not have HD Radio equipment in their cars or homes and the radio stations would lose a lot of listeners if they didn't have the FM broadcasts.
Finally, satellite radio is a joke. My car came with 6 months of free Sirius/XM and I played around with it for a couple days before deciding it wasn't worth using even for free. The sound quality is horrendous. It sounds like a 96kb MP3 stream from the 90's. It also cuts out under every bridge and when the road is lined with trees on the south side (which is a lot of roads in Washington). Apple Music offers much better sound quality and the ability to choose any song I want for less money.