There's something quite specific keeping FM going too.
Additional to the other users of FM local football has a big part to play here,
For many people it's the only way of getting coverage for their team, and the money grasping nature of the way it is licenced mean that said stations can only broadcast it in their local area. i.e via FM. Stations that offer output over multiple / types (DAB, FM, MW and online) are made to replay random pre-recorded shows on the others and just broadcast football via FM (or else pay through the nose).
Or in areas like mine with multiple teams FM will carry one, and MW the other. Or one frequency of FM carries one and another frequency carries the other etc.
It's a dead specific "use case" but it is a thing, and in quite large numbers in many areas.
If you support a team not in the top tier, it's often the only way available to those who don't trust/won't or can't pay for the online streaming all teams now put out, and even then they aren't allowed to stream the 3PM Saturday games to UK punters etc.