A great use case that I can think of right of the bat, is protection of patient data, making it immutable once stored.
i guess the real important question is, what is wrong with current way of storing and protecting patient data? we have been using it for years and there is no problems with it which means there is no need for any change. it is basically a the database, and we don't need to change this database from its current form to a new database form called blockchain.
Obviously, we're now in a blockchain craze that everything in our environment needed to be use the blockchain claiming it will be economical and sustainable in the long run which is not at the first place.
Not just because this is what the technology dictates it shouldn't be necessary to do so considering this is a health issues that everyone thinks needed a privacy.
I think it boils down to the protection of consumer data. For example, 1.5 million health records were stolen in Singapore: