> Additionally, with FM you need to make sure no transmitters on the same frequency can cover the same area, as that would lead to interference.

In the UK the BBC transmits their FM channels on the same range across the whole country [0]. In most cases the frequency between transmitters is only slightly different (e.g. 88.5 vs 88.1), so it can be picked up without having to retune the receiver. It requires a bit more thought up front, but it’s not that difficult (compared to other considerations you need to have for tranmitting radio), and it’s a much better UX than having to remember different frequencies for the same station in different cities.

[0] http://downloads.bbc.co.uk/reception/pdfs/FMradiotrans.pdf