What if it was as good as it seemed to be on Star Trek? You know, with the computer able to recognize he meant hot water flavored with dried leaves. A computer several hundred years more advanced than the ones you expect to have those problems with.
That computer wouldn't need your voice because it would have to be reading your mind. That's not how it worked in Star Trek. The AI doctor in Voyager might be a better example, as he observed all of the surrounding context, had real communication with people, etc.. but that wasn't at all how their computers worked. The computer was given commands and did them. The actions that made the most sense are already features in smart speakers, and had little to do with actual computer use.
And in what case was which captain giving orders to the computer instead of their officers? If Picard said, "Fire torpedoes", he was talking to Mr. Worf (or whoever was manning tactical), not Majel Barrett's disembodied voice.
I never mentioned who was talking to the computer. Let's say Picard told Worf, then Worf had to tell the computer. Even Star Trek doesn't pretend that will work! Worf has a terminal he uses to do the actual stuff. The computer is often relegated to making tea, adjusting the lights, or opening a short comms link.
TBH, I think that gets at the actual uses. What do we use our smart speakers for today? They *can* do a lot more than we use them for (ex. I never buy products via Alexa, nor do I have it send emails or know my contacts), but they mainly get used to tell me the weather, time, adjust the lights, play some music, convert imperial to metric, ... easy and straight forward stuff.
I suspect this will be much like a touchscreen on a computer - occasionally convenient, very useful in select situations, and awful for day to day work. One of the most useful things I can think of would be diction, but that's been available for decades. Text to speech could have some uses, but book publishers (the things I'd want read to me the most) have already blocked that where it was readily available (even the first Kindle could do text to speech on any book... but only those with the right licensing so they didn't step on Audibles profits). The accessibility community should benefit quite a bit though, and that's a good thing.