The difference is only significant if the radio station uses a sufficient bitrate. There are some with atrocious quality in DAB because of their low bitrate.
I can only speak for the UK, but FM here sounds considerably better than DAB because stations on DAB are usually 32 or 64kbps & mono since they want to fit as many stations into the multiplex...
(techmoan has a rant about it— https://www.youtube.com/watch?v=27w3quNTP84)