I was not aware of this until now
My main radio listening is in the car.
My car is currently 10 years old and when I replace it it will be with a car at least 3 years old so very unlikely to have a radio that can receive DAB.
While I have not investigated I guess many new cars do not have DAB radio as standard.
Also now car radios are less easy to replace/upgrade.
There is live a government petition campaigning to retain AM and FM radio