The removal of FM radio from cell phones was a big mistake. It should never have allowed. Radio is very useful in emergencies. Lately I have been getting back in to internet radio, mostly via Elisa in KDE. Here is my favorite internet stream: https://hawaiireggaenetwork.com/
I don't think I ever used the FM feature on my phone, except purely to test out whether it worked. I wouldn't make phone purchasing decisions based on whether or not it had a FM radio. A regulation requiring it in the ostensible name of safety would make phones somewhat more expensive and I'm skeptical that it would even help improve safety in an emergency significantly.
"somewhat" as in the ballpark of a few cents, definitely less than $1, because it's already there in the reference designs and deliberately removing it would actually take extra work and cost far more.
I remember all the no-name/generic MP3/MP4 players had an FM radio, while Apple's iPods did not. They deliberately chose not to include one, and definitely not because of cost.