Well, I managed to find one game out of your last ten or so bullet games where you opened with 1.f4.
But none with 1...f5.
If you're talking about Bird's opening (1.f4), skilled players do use it. It's got a fair reputation as a sound opening.
It's just another wing opening. You can transpose into the King's Gambit depending on black's reply.
The "From Gambit" is a common defense when black will reply 1...e5 to attack your f4 pawn.
I have been opening with 1.f5. The results have been +ve mostly at my level in bullet. I am sure that skilled players don't use this opening for good reason. What am I missing? Thanks,