Google Voice Search used internal codename "Majel" in reference to Majel Barrett, who played the voice of the Star Trek computer. That was explicitly the ambition. It just didn't work out.
I guess where we disagree is "very useful". If Google Assistant stopped working tomorrow I would hardly care at all. There are a couple of scenarios where it's slightly more convenient than using my phone (assuming I don't encounter one of its many failure modes) and that's about it. I'm sure the hands free aspect is important for certain people in certain situations but I think the vast majority of people just don't see a lot of value from it.
Those sales were subsidized in expectation of future profitability that will never come (at least not without a ground-up redesign of the product around LLM-based AI agents or some other paradigm). Economically Alexa is a "colossal failure": https://arstechnica.com/gadgets/2022/11/amazon-alexa-is-a-co...
But how often did that computer voice-acted by her really do significantly more than "set timer to thirty minutes"? Outside of some broken plots on the original series ("we have insufficient data to know the truth, let's ask the computer who will tell us anyways!"), it really was mostly mundane voice assistant stuff.
(I'm deliberately excluding the "ten words to 'author' a holodeck scene" part, that had always been stretching my imagination a little too far, more "this can't work!" than space travel and transporter beams. Then stable diffusion happened)
There were some scenes where Riker on the bridge asked the computer essentially a SQL query: "give me a list of star systems with parameters that fit X and cross-reference by Y..." "There are 3 systems which fit your query: ..."
That might have been the initial hope of the team, before Google killed it. It's been on the graveyard for years with zero updates, my google assistance nest mini is arguably worse than when I bought it.
I believe it is possible to have made it better, but they didn't try, they just gave up, like much of google products.
Is that a story of failure or of success?
Starbucks launched to sell beans and espresso machines. YouTube launched as a video dating site. Are they also failures?