What's obfuscated is the _actual_ semitone interval between the accidental and the other notes around it. And the actual semitone interval is the most important bit of information - it's what our ears hear.
I think what you're missing is that a big part of the design of traditional music notation is that it is intended to be read easily and efficiently, even sight-read. The musician reading the score knows the intervals that apply in the given key, down to muscle memory. The fact that a note lies outside the key is important, and that is why an accidental is marked explicitly.
Likewise, when a musician sees a run of adjacent notes without accidentals, they immediately know what to play. They don't need to inspect each one in turn to determine how many semitones it lies from the previous note. Likewise, when a composer wants to write such a run, they can just draw some black dots in a row. They don't need to squint at a grid and select the correct rows each time.
To sum up, traditional notation is uses a form of compression that makes reading and writing diatonic music easier.
Taking this even farther, some systems of music notation compress things even further and don't explicitly list all of the notes to be played. For example: figured bass, basso continuo, or even just chords that accompany lyrics. In fact, even regular sheet music doesn't usually precisely represent of duration of all of the notes. Some notes are sustained and bleed into others, some are meant to be played strictly in time. Human interpretation is an important part of the process.
On the other hand, the piano roll is a MIDI editor. It is a great way to tell a computer exactly what to play, but it is not easy to read quickly and it is impractical to print or write by hand. Both forms of notation have advantages and disadvantages but it seems to me you haven't spent enough time with the standard notation to fully appreciate its advantages. In other words, the piano roll notation might be your blub language for music. [1]
Fine. But I'm saying if you want to actually understand how music works (rather than play an instrument) the standard notation IMHO
actually gets in the way.
Because the most important thing is the actual semitone intervals, and the standard notation hides them and gives them weird names like augmented fourth (it's just six semitones, just call it that). And it names the 12 semitones based on the c major mode even though that's only one of about 50 modes/scales/keys you might want to use.
