Update:
I found out this post Ability to limit the scope of a relation, which is not too different to my idea of treating relations as object in a way that you can either link them or use them in a hierarchy; i.e. relation as animal with subcategories like dog breed.
Or for example in a workout scenario, you have a relation called “exercise”, you can not only choose “bench press” as an object for it, but also you can limit/relate other relations(aspects) like “reps”, “sets”, “duration”, etc to it.