It will be a long time before that happens in Home Automation for any Device class. 
As the old saying goes “all home automation is local.” There are just a lot of variables, including the strength of the mesh, building architecture, even the weather can make a difference. So what works well for one person may not work well for another.
As for options for a button, so far everything that has been mentioned in this thread is also listed in the buttons FAQ, plus a number of other options, so there are a lot of choices. 
One thing I did want to mention is that due to the nature of Zwave and zigbee, battery powered buttons may always be a little flaky. Not terrible, but maybe 1 to 2% of the time you’d have to press a button twice. That’s because in order to make battery life longer, these devices “sleep” in between uses. And every so often one will be asleep and then you have to wake it up before your message gets sent.
Mains powered devices don’t have this issue, and that includes voice options. Now that Amazon has added room awareness turning lights on and off it’s even easier – – whatever room you are in, you just say “echo, turn the lights on” and the lights for that room will come on as long as you have set up a group to do that.
We have a lot of people coming to our house as we are three housemates with friends and family, plus health aides. The new echo – enabled groups have really simplified instructions for visitors. 
But of course sometimes you do want a silent option, and the buttons can be great for that. But even the best of them will have a higher failure rate than a mains powered device because of the sleep issue.
All of that is separate yet again from the Xiaomi issue, which is dropping off the network all together, not just being asleep and needing to be awakened. So there is a difference between brands and models as well.