While receiving analog radio is trivial for the processing required, it is fairly low frequency transmission which requires antenna sizes which are not entirely practical for phone-like device. I would even assume that many phones contain the required hardware (which usually involve using headset cable as antenna) but don't have any kind of software support for it because of combination of minimal demand for such a feature and the fact that the entire experience is not exactly user friendly. Notably, Raspberry Pi uses wifi/BT radio which apparently either includes FM radio or used to in previous revisions (and apparently the radio chip is capable of receiving FM and directly sending the audio to BT headset, which is somewhat interesting feature given the usual requirement of wired headset as antenna).

I think the main reason that phones don't have broadcast AM and FM enabled (even though the hardware is present in the chips), is because the digital chips in the phone (micro-processor etc) would generate so much interference (at these relatively low frequencies) that it would be unworkable. To sufficiently shield the main PCB would require a huge effort, which means weight, size and cost.

To get an idea, you only need to hold your AM/FM radio near your PC or Laptop.

FM radio works pretty well on a lot of smartphones.

An antenna perhaps as long as a pair of headphone wires?

I figured it would come down to antennas.... but I am still disappointed...

AM/FM is really up to the handset manufacturer, some phones have the hardware turned off by the manufacturer.

A number of phones, including my Samsung Galaxy S10e, have the built-in FM radio enabled. It needs to have a earphone plugged in, which it uses as the antenna. The app is NextRadio.

I had a very cheap Android phone for a while that had this. Unfortunately, later flagship phones I got seemingly did not.

Dope - is there any IOS equiv app? (or is this avail om IOS?)