Siri and Cortana have to run at least in real time, with reasonable compute resources. Probably faster than real time when the audio gets shipped off to the cloud and transcribed there. This model can't do that (in the "large" version, which the examples use).
Also, you are comparing Whisper's highlight reel with everyday performance of other models. Nobody shows their weaknesses in their highlight reel.
Also, you are comparing Whisper's highlight reel with everyday performance of other models. Nobody shows their weaknesses in their highlight reel.