fm radio is a lot easier than dvb-t or whatever. or the mobile dvb that was tried and killed off already. seriously, nokia had model(s) with digital tv ages ago.
even analogue tv is much easier and cheaper. that's why all those chinese clone-fake-gsm-2-sim phones have analog tv support.
what the fm radio needs is couple of traces and a cap on the board.. even if you put an extra chip on there it would be easy and cheap to do. people just don't use the fm receive functionalities in the phones that have them so people don't give a shit. tons of cheapo nokias had fm-receive for 10+ years now. it's just a 20 cent functionality.
nobody just gives a shit about fm radio when shopping for a new phone if the phone has enough gizmos to play spotify. that's just the way it is.