Inconsistent dictation on MacBook Air despite working on iPhone 11

Nothing works consistently. Neither the shortcut I chose, nor the F5 button, nor the Start Dictation in Edit work consistently. Especially in the latter, sometimes the microphone symbol appears but nothing happens when I speak. This has been the case in all system updates and all previous Macbook Airs I have had, yet my Iphone 11 dictation works fine. Is this something that Apple has just failed to perfect? Frustrating.

[Re-Titled by Moderator]

Original Title: Dictation difficulties