In my own (and limited) experience, whiff cancel gets fucking destroyed by frame traps. Keep in mind a VERY important aspect of whiff canceling: they can only do something that has a hitbox so if u use a move out that'd hit them relatively fast they just wasted the burst to get counterhit instead XD.
Also if u suspect there might be a whiff cancel incoming bc u outspaced them or something like that u can use a free cancel on the punish move. If they dont whiff cancel u get the free cancel back since u did hit them and it wasnt a combo. If they do whiff cancel u get to adjust accordingly (they must throw out a move) and either parry, use an invincible move with Iniciative or just change your position so they whiff again and then cash out.
But again this is from my limited experience so i might be wrong lol