The tempo loss of Gush is too heavy of a burden in most formats. Vintage can take advantage of the mana / card advantage Gush can provide since it can draw into more free mana / card draw (like more Gushes) all while fueling Monastery Mentor / Young Pyromancer.
Any body remember when Quirion Dryad used to be a thing with Gush?
Any body remember when Quirion Dryad used to be a thing with Gush?
My High Octane Unpowered Cube on CubeCobra