I really wish these various voice offerings would offer push-to-talk as an option. It would solve a whole bunch of problems: It would activate reliably when you want and almost never accidentally, you don't need to use awkward code phrases, and it can trigger results as soon as you release the button instead of having to wait for silence. It would also allow for better privacy by making a phone in which the microphone is hardware controlled by the button.
It just seems so obvious to me that I don't know why no one has done it. I guess needing a new button makes it harder to sell, but this seems like a great use case for smartwatches.
I know some technophiles coworkers who have an Echo, and I couldn't for the life of me trust Amazon, Google (or even Apple) with potentially the always-on stream of audio from my house.