I think the general public cares quite a bit about these things, maybe not to use the data themselves on that a granular level like the users of this forum. But reasonable data exports in standardized, machine-readable formats are import to people nevertheless for other reasons, e.g. to avoid vendor lock-in or being able to share data with healthcare providers.
I’d also argue that if there wasn’t a public demand for this kind of data exports that the EU wouldn’t have bothered to make that one of the user rights 