There's plenty of use cases, just because you can't think of them doesn't mean there aren't any. Neural network based audio codecs like TSAC, Descript, Encodec, Soundstream are used for music and speech generation, audio upsampling, pre-training acoustic language models, speech-to-speech translation etc.

Check out the citations of Encodec (Facebook's open sourced audio codec) for more examples: https://scholar.google.com/scholar?cites=1126914113099467682...