Each language/notation system provides a fluency but also imposes limitations on the expression of creative ideas. Our current (Western) music notation system is based on an archaic modal framework. Accidentals were added later, to accommodate an expanded chromatic pitch system. Temperament methods (n-limit just intonations, meantone, equal temperament, etc) were then added to accommodate tonal modulation and harmonic intonation within a chromatic system.
In many cases, notation (symbol) evolutions are a secondary effect of advances in theoretical terminology (nomenclature). Pitch (note) duration terminology has evolved in specificity from indirect, esoteric and cumbersome terms (crotchet; hemidemisemiquaver) to simpler quantified terms (quarter note/rest; 64th note/rest). By indirect, I mean note definitions like: "the value of a quaver is one eighth of a semibreve, or half of a crotchet". Direct terminology skips the step of esoteric translation: the value of an quarter note is 1/4 of a whole note, 1/2 of a half note; the eighth note is half of a quarter note, etc.
As musical languages continue to evolve, the larger problem becomes: how much longer can ‘bolt-on’ expansions to a simple modal (7 pitch per octave; A-G) notation and theoretical framework suffice. One modern example is microtonal (>12 pitches per octave) music, which is pushing modal notation and modal intervallic theory to its endpoint. As a result, we see an increasing notation 'discordance' in the continuing invention of numerous, incompatible pitch-modifier symbols (accidentals) necessary to notate musical ideas beyond the limits of a chromatic (12 pitch per octave) system.
Pitch (note) duration terminology has been updated to the modern era in its quantitative basis. It has a dual complexity in notating a wide array of simplified, absolutely-defined duration relationships (half note=2 quarter notes), as well as symbolizing a contextually adaptive structure: accommodating flexible variances in the temporal duration of a quarter note (in seconds), relative to tempo or pulse. However, the underlying modal system and theoretical framework of music is proving to be much more resistant to modern evolution.