My first guess would be "Open hacker news" requires clear audible speech. While the KB method just requires pressing 'h' and 'enter'. Also, non-cloud speech recognition just recently got decent.
Context matters with such shortcuts. Even if I make sure that I have the location bar selected, focused and clear, 'h enter' takes me to a completely different website - because hacker news is actually 'news.ycombinator.com', so it's not the default by typing'ctrl-k h enter'.
And let's be frank. Even if we do get voice control, it's not going to somehow take our keyboards and mice away from us.
In principle there could be voice shortcuts; currently there seems to be an expectation that voice interfaces should be entirely limited to natural language words and sentences, but if we're willing to let this constraint go (at least for "power user shortcuts") and just design bespoke syllables in IPA or whatever, we could probably come up with something more efficient.
It also ought to be possible to specifically design interleaved voice+keyboard, voice+mouse, voice+touch, voice+pen, etc. interactions that could be more expressive and efficient than either input method by itself.
Context matters with such shortcuts. Even if I make sure that I have the location bar selected, focused and clear, 'h enter' takes me to a completely different website - because hacker news is actually 'news.ycombinator.com', so it's not the default by typing'ctrl-k h enter'.
And let's be frank. Even if we do get voice control, it's not going to somehow take our keyboards and mice away from us.