The point is that blockchains don't provide you with anything other than that "main use". For any other kind of feature you need to add something else - and if

The point is that blockchains don't provide you with anything other than that "main use". For any other kind of feature you need to add something else - and if you're adding a centralized trusted authority (which is by far the easiest way to do anything), then you can get rid of the blockchain altogether.