Just putting my two cents in.

The station I work at used to properly use RDS, we displayed the current song, station name and alternate frequencies (though we only have two because we use GPS synchronous tech to broadcast from multiple sites on the same frequency). Sadly, the unit died, so now we just have a static text that provides alternate frequencies, but fingers crossed it will be fixed at some point.

Some other things RDS has is traffic announcements and time data (I guess for updating the car clock?).

Some exciting tech I've been told about is the ability to have dynamic RDS depending on the transmitter location, so in theory we could broadcast traffic announcements just for that area. Something to play with at very least.