With hindsight I regret being so critical of other (than Apple) systems as in all honesty my experiences are out of date.
Sticking with Apple, and despite the fact I'm beginning to sound like a one-man advertising campaign, I wonder whether one reason it is becoming really quite good is that they are turning out devices that strongly encourage real-world use of the technology?
People worry, of course, over the privacy issues of voice data being uploaded and stored on servers. But the upside of that is,
I'd imagine, that the more the more the system is used, the better it will get? If so, then providing a system where voice recognition actually fills a need, with strong incentives to use it, ought to make for a better system.
The Apple Watch wouldn't be a great deal of use without Siri IMHO, and so it does get used. And with the new TV, quite apart from searching for films etc by name, justifies itself from the simple ability to say things like 'rewind 25 seconds' during film playback. Even over the *background sound from the film's soundtrack (and I have a very beefy sound system), it works very reliably indeed and quickly becomes second nature for playback control, so it actually gets used too.
edit... * fair to admit, it does seem to reduce the playback volume somewhat during speech input. Still impressive though.