Actually, now that I think of it - the Samsung remote that my mum uses, has quite a higher failure rate than what I am used to. Although, that is pretty much down to a low battery and I think the buttons, which are rather big (and cheap) don't always register nicely when you press them. The transmitter also seems to lag a bit more compared to mine, which could be down to the battery or the quality (or the fact that it most likely has been thrown around and dropped a few times).
Bear in mind, my own remote isn't anything hightech and the IR remotes I've been using all work flawless in that - yes, I can state - they are pretty close to 99% and if there is a failure, it's usually down to user error (e.g. me pressing a button too quick after another one or being too far away).
I think I would notice, though I accept your point as well that you tend to overlook these things when they do occur. On the other hand, I suspect this is also down to it being a rather small annoyance - namely because the feedback is instant. Using voice-controls isn't - because already the command 'xbox. one. do whatever' already requires around 4-5+ seconds (I'm guessing here, as Xbox. One. already takes around 2-3 seconds), so it not registering means a higher loss in time, ergo more noticable annoyance. Also, I suspect there is a small gap between when you complete the command and when it's executed on the system (after all, the Xbox also needs to figure out that the command is completed?).
Fair enough if people are happy to tolerate this. I'd still be quite interested to know if when these failures do occur, how many retries are required (on average) until the device does the command as requested. Surely, this has to be a lot more complex (and therefore error-prone) than simply repressing a button on a remote?
I'm happy to say that if I was forced to use voice-controls for a very specific task - like on a device to play games and only to play games - I'd be happy to give it a much higher tolerance. However, within the context of my livingroom and controlling my AV systems, I wouldn't really put up with it, as I'm used to a flawless working remote. The benefits would need to significantly outweigh the cons, but even then, for some things, I prefer simplicity and reliability over complex and less reliable methods - especially for inherent simple commands (start, stop, play, pause, volume controls, channel numbers, menu navigation etc).