Siri has a huge latency problem. I say "Hey Siri" and its' precious seconds before she's listening (articles online tell us that it's possible to just ask the entire question without waiting for the beep -- but doesn't work, sometimes Siri's just not ready.). Someone at Apple clearly needs to reengineer Siri -- I say this as someone who's bought into the Apple ecosystem.
Siri is the like the Apple Maps of voice assistants.
Alexa (at least Echo gen 3) doesn't have this delay. I can talk with Alexa without getting frustrated at the latency. (unfortunately Alexa doesn't handle pauses or stumbles in sentences well)
it is interesting. I don't get exhaustion because I don't talk to the assistants that much, but people talk to their virtual assistants in a different cadence or register. Instead of "alexacanyoutellmethetime?" it is "ALEXA...WHAT...TIME...IS...IT."
Owning an Alphabet Corp Branded Espionage Hockey Puck (tm) myself, I must admit I'm fairly impressed at how far voice recognition and natural language processing has come, despite this. I remember when you really had to talk in that stilted, properly pronounced, methodical way, and then tentatively wait for a response for what seemed an age -- and it wasn't that long ago (maybe like, four or five years?). Nowadays, I can vaguely mumble at mine from the other room without thinking too much about sentence structure or how I'm pronouncing words or the volume or speed of my dictation or switching off things making background noise, and it usually does the right thing, and responds about as quickly as a person. It definitely feels a lot less mentally draining!