In my opinion Hendrix is to electric guitar what Beethoven was to (Western) harmony. All contemporary lines go through him.

One thing to note though is that Hendrix had a very short career in which he lived/performed in Nashville, the Chitlin' Circuit, Greenwich Village, and London. On top of being an incredibly proficient/creative guitar player he also had an incredible ear and picked up sounds/techniques/songs from everywhere he lived and with everyone he played with.

Part of why you can trace the evolution of guitar playing through Hendrix is that on top of his records being popular and everyone learning those tunes as a first/second year student, his own musicological background was a fusion of the major songwriting movements of the 1960s that spawned modern blues, pop, funk, fusion, rock, and metal. It's easy to see Hendrix as an influence on modern music because he was a magnet for players of all those genres.

What's interesting about Hendrix is that he is "an artist you listen to" instead of "an artist who an artist you listen to, listens to" from the same era like Albert King or Joe Pass.