3...g6
Parham Attack
2... Nf6 3. Qxe5+
Yeah, but that's one of the ways to play, the pawn sac line. IIRC it's better for black (but I always play Nc6 + g6 so I don't really know).
its not that bad, but most people that play it are patzers so they wont play the best continuations.
Yeah, there's some video out there of Carlsen playing against it in blitz.
Carlsen wins, but just barely. White gets a completely fine position.
I find OP's claim to be most dubious.
https://www.chess.com/forum/view/chess-openings/establishing-parham-theory
This is clearly the best opening in all of chess and i cant understand why most people dont play it.
If anyone can refute this please do so, I have yet to find a line that does so.