People say g4 (grob) is the worst opening move, but I'd argue it's f3 by a long shot.
Playing f3...
- Weakens the king (g4 also does, but not nearly as much)
- Develops no pieces (g4 develops a bishop, if only a bit awkwardly)
- Doesn't even try to get center space (g4 does...kinda)
- Blocks your knight's good square (g4 does not)
- Is the only opening move considered a mistake ("?") by Stockfish (g4 is not)
f3 may be the worst first move for White, but remember: Black has something far worse.
Damaino: Qe7 exists.
I have analysed this, and I guess that fact must be so. However, after 4. Nf3 Qxe4+ 5. Be2, I think you will find that Stockfish thinks White is winning at an advantage of +1.98.