That's actually (sneakily) not the case. Gboard does have voice transcription, but it's triggered by pressing the microphone button at the upper right corner of

That's actually (sneakily) not the case. Gboard does have voice transcription, but it's triggered by pressing the microphone button at the upper right corner of the keyboard. Apple's voice transcription is still triggered from the bottom right button, even if a 3rd party keyboard is being used.