I think if Dolphy had lived longer, he would have eventually been viewed at the same level as Coltrane or Mingus. His sound was sometimes like Monk playing brass.
He sure left the stage early and for all the wrong reasons, but to this saxophonist-flautist at least, Dolphy already is on that level. At the Five Spot changed everything.
For me it was "Out To Lunch" and the live concert in I think 64, with Mingus. He just shone. A few years back I did an exhibition of jazz portraits at the now defunct Cafe Stritch where he was one of the bigger prominent works: https://www.deviantart.com/zeruch/art/eric-dolphy-v5-1936648...
I think its the phrasing that just does it for me.