What's driving them to kill analog FM so abruptly? For one example, the USA had an overlap of over 2 years between when (digital) ATSC receivers were mandated

What's driving them to kill analog FM so abruptly? For one example, the USA had an overlap of over 2 years between when (digital) ATSC receivers were mandated for all TV equipment and when the analog signals were actually cut off. Have they already reassigned/sold that spectrum? Lots of mobile devices and small electronics have FM receivers with the advent of cheap FM chips, including some of my phones and even my US$10 Bluetooth headphones. Are there cheap parallels for digital FM receivers?