Roman numeral analysis uses capitalization to disambiguate Major from minor, so the paradigm is not entirely based on inference. There seems to be a double standard as to what is explicit and what isn't. The most prominent example is the lack of distinction between a Major 7th chord and a dominant 7th chord.
- Both Roman numerals are capitalized
- The figured bass suggests the same inversion
However, they are both representing different qualities. There is no quality symbol suffix (Δ, Maj, or Dom) to disambiguate them. This is especially confusing, because this syntax clashes with the syntax of jazz/pop chord analysis. "X" (the alphabetic root of the chord) immediately followed by 7 signifies a dominant chord quality in jazz/pop chord analysis (see the chord symbol underlined in yellow).
Additionally, using the syntax above, you'd have to contextually think about the scale degree of the chord in order to inference the quality of 7th chord you are dealing with, which presents added hurdles for both beginners and modern learners versed in jazz/pop syntax.
Why not explicitly include quality symbol suffixes for seventh chords (such as -, Δ, Maj, Dom, etc.) like in the manner below?
Common practice composers didn't consider dominant seventh chords to be stable entities, which is a large reason for the lack of disambiguation. In music of that era, V7/IV is a more functionally appropriate way to describe a dominant 7th chord built on the first scale degree. But in the modern age, in the music of Gershwin, Ravel, or jazz and blues in general, the I7 can function as an entirely stable entity, devoid of any secondary function at all. Hence, I think Roman Numeral analysis should take some cues from jazz chord analysis and become a bit more explicit.