I don't have a good analytical response to this. Your comment doesn't pass the smell test for the following reason: I am a fairly serious jazz guitarist, and it seems to me like most great guitarists can be quickly identified by ear after playing three notes: Charlie Christian, Joe Pass, Blind Willie Johnson, Mary Halvorson, Django Reinhardt, etc. In some cases just one note is enough: B.B. King, Wes Montgomery, T-Bone Walker, Jimi Hendrix. (60 years later and still nobody plays octaves as well as Wes did).

Obviously some of their sound is tied to specific guitar models, but their tone is still easily identified on other guitars. And although these players were creative improvisers, that's not what I mean. Simply put: if it's a great guitarist, you can hear their hands like you can hear a singer's mouth. (Though hands are clumsy compared to mouths, and guitars are clumsy compared to horns.)

I am not anti-synth or anti-electronic music. But I do not believe any existing synth controller provides the expressive possibilities of an electric guitar, even Allan Holdsworth's goofy breath controller. Maybe I'm wrong and there's a great example out there on YouTube. But it seems to me that for an individual to express their individuality with a synth, they need to play a longer musical fragment and color their expression with timing, volume, vibrato, etc. Three notes "with pizazz" will not really be enough.